How to Choose a Backpack
REI Co-op Flash Air 50 Pack - Women's
$299.00
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Inspired by thru-hikers across North America, the women's REI Co-op Flash Air 50 pack is our lightest backpacking pack yet—perfect for those who like to stretch the miles without sacrificing comfort.
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- Ultra-high-molecular-weight polyethylene (UHMWPE) fabric is amazingly durable and allows for a surprisingly long lifespan for such a lightweight pack
- Nonfluorinated durable water repellent (DWR) helps moisture bead up on the surface
- 3D contoured hipbelt and ventilated back panel are comfortable all day for loads up to 25 lbs.
- Roll-top lid provides weather resistance and allows compression and adjustment of internal volume
- For a tight load and good balance, Packmod compression straps (included) can be run from any loop to any other loop, so you can sculpt your pack to the shape of your load
- Packmod mesh pocket on the shoulder strap is great for phone, snacks, sunglasses and more—or you can take it off altogether to reduce weight
- Compatible with Packmod hipbelt lengthener and Rainshield pocket (accessories not included)
- Water bottle pockets are positioned forward on the hipbelt so you don't have to remove the pack to grab your drink; cinch closures keep a good grip on slim water bottles
- Exterior side pockets and hipbelt pockets are great for storing light items that you want to keep handy
- Large front pocket is great for rain shell or other gear you may need to access quickly
- Top Y-strap helps you store excess items, including some bear canisters, on exterior of pack
- Attachment loops and removable tool keeper allow trekking poles, ice axes and more to be lashed on, expanding your carrying ability while keeping the load stable
- Daisy chain with multiple attachment points allows for tailoring exterior loads
- Internal hanging loop secures a hydration reservoir (not included); pack design allows tube to be routed over either shoulder
- Also comes with a handy mesh pouch (6.3 x 8.7 in.) to store or organize removed Packmod accessory straps or other small items
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
- Contains materials that meet the bluesign® criteria
Imported.
View the REI Co-op Flash Product LineView all REI Co-op Backpacking Packs| Best Use | Backpacking |
|---|---|
| Frame Type | Internal Frame |
| Ultralight | Yes |
| Gear Capacity (L) | XS: 49 liters S: 50 liters M: 51 liters |
| Gear Capacity (cu. in.) | XS: 2,990 cubic inches S: 3,051 cubic inches M: 3,112 cubic inches |
| Weight | XS: 1 lb. 12 oz. S: 1 lb. 13 oz. M: 1 lb. 14 oz. |
| Fits Torso Length (in.) | XS: 16 inches S: 17 inches M: 18 inches |
| Fits Waist/Hips | XS: 30-38 inches S: 32-40 inches M: 34-44 inches |
| Material(s) | UHMWPE ripstop nylon (87% nylon/13% polyethylene; bluesign approved) |
| Frame Material | Spring steel |
| Reservoir Compatible | Yes |
| Pack Access | Top |
| Number of Exterior Pockets | 8 + main compartment |
| Raincover Included | No |
| Hipbelt Pockets | Yes |
| Dimensions | XS: 24 x 14 x 12 inches S: 25 x 14 x 12 inches M: 26 x 14 x 12 inches |
| Gender | Women's |
| Sustainability | Contains materials that meet the bluesign® criteria From a Climate Label Certified brand |
Buying Advice
Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.
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Most Helpful Favorable Review
I'm Seriously Impressed
almk1 year ago
Received free productI was a bit wary of an REI product that was so lightweight. Ultralight backpacking packs are hard to make well, but this was a goodie. Keep in mind that this review is from the perspective of AN ULTRALIGHT BACKPACKER (if you aren't looking for an ultra lightweight pack, this is not the pack for you. There are better mid-weight packs out there that will make you happier. If you load too much heavy stuff in this pack, you'll hate it). Here are my favorite aspects of the pack after a full 3 day trip:
1) it's huge (for a lightweight pack). Most ultra-lightweight packs are small and lightweight. I hate that. It becomes hard to load up and you end up wrestling with the lightweight fabric trying to jam all your stuff into it. I like having extra space that I can then cinch down. For my 3 day trip, I was able to easily fit: 15 degree down sleeping bag, extra long sleeping pad, 2 person tent and poles, jetboil, accessories (such as headlamp, batteries, charging block, cords, water filter...etc), down jacket, raincoat, and my sit pad. There was still plenty of space for other things. My particular trip didn't require a bear canister, so I was able to put all my food in a bag and I hung it on a tree to keep it away from critters. However, you could easily fit a single person bear canister inside the pack if necessary.
2) it's comfortable. If you don't overload this thing (again, it's an ultralight pack and not intended to be loaded with non-lightweight gear) it's an extremely comfortable carry. The padding is nice and there's some space between the back panel and your sweaty back. That is unique for a pack like this! There's an actual internal frame to it, unlike other similar packs that don't have an internal frame.
3) features are minimal, yet sufficient. Ultralight packs are intended to be minimal. There is no top brain, and only one outer stuff pocket (which also cinches down). I found that plenty sufficient for my needs. The cinch straps are easy to understand and operate, making it easy to use. The top cinch strap is removable, but I used it for my sit pad since I wanted quick access to it and it also helped compact my gear even more for an easier carry. The water bottle pockets are amazing. I love them. They're great, just believe me. Also, the hip belt pockets are big enough for snacks or small accessories. Trekking pole attachment is minimal, but functional. There is a sternum strap whistle.
Thing to pay attention to before you purchase:
1) Be sure to look at the sizing. This pack does not have adjustable torso length, so your only adjustments are in the shoulder straps, load lifters, sternum strap, and hip belt. I'm 6 foot, with an 18 inch torso length and the medium fit great. Oh, and another small feature that I didn't realize I ever needed: the sternum strap does not have a blocking stitch when you slide it up and down. It is fully adjustable vertically without the need to remove a clasp. This is perfect for adapting to different breast sizes. I appreciated this.
2) do you like using water bladders or water bottles? I'm a water bottle gal, but there is an internal hook for a bladder. However, it looked to be a pain to operate as the internal sleeve also seems to house the internal frame. I'm willing to bet you will struggle with putting a bladder inside, especially with a full pack.
Overall, I liked it a lot. I would recommend this to anyone looking for an ultralight backpacking pack.
almkReceived free product
Tucson, AZ
26 people found this review helpful
Most Helpful Critical Review
Broke
NJS1 year ago
Great pack and super comfy, until the strap snapped on my second hike. 😕 REI says I’ll need to get it repaired myself, since I’m not the purchaser and I don’t have the receipt. The pack was brand new.
NJS
24 people found this review helpful
Customer Images
khike7
Received free product
Redding, CA
Quality UHMWPE fabric, comfortable ultralight pack
1 year ago
The REI Co-op Flash Air 50 Pack is an ultralight-style pack utilizing durable UHMWPE ripstop nylon. Size Medium weighs 1 lb., 14 oz. for 51L capacity (3,112 cubic inches). In an ultralight pack, there is often a trade-off between positive “lightness” and the pack’s functionality. This is my impression of the Flash 50. I saw on REI’s website that someone had asked a question about the pack’s seams. REI Service responded: “This pack is not seam sealed to be waterproof.” Like most packs, the Flash 50 requires a pack cover in bad weather. As my first test was in pouring rain, I had to find a pack cover in my stash. I chose an older Dana Designs cover that is large, but amorphous in shape, with a drawstring cord to pull it tight against the pack. The cover performed well, but the trick was to find tie-on points on the pack itself. To solve this sort of problem, I wouldn’t recommend the Flash 50 as one’s first backpack. Accessories, like NiteIze ties and mini-carabiners, are useful to attach stuff. I was able to jerry-rig suitable, secure attachment points for the rain cover. Obviously, photos were taken on a sunny day, but I wanted to show how well the pack covered the sides and bottom of a moderately stuffed Flash 50. Other accessories in photos: a large strap pouch and hand saw in black sheath. My other way of dealing with rain--including protecting electronics--was to use dry sacks to line the main compartment and the back, kangaroo-style pouch. When camping, I want to easily pull out a bundle of clothes or gear and not have individual items loose in the main, single compartment. For starters, I chose an OR (Outdoor Research) 35L sack for the main, single compartment, a Sea-to-Summit 13L Big River Dry Sack for the back pouch, and an Osprey 6L Dry Sack. One needs to experiment to suit one’s own gear and trip needs. I give the Flash 50 a 4-star rating for its comfort, light weight, UHMWPE fabric, and multiple side pockets. However, the space in the main compartment fills up quickly, and attaching large objects to the exterior of the pack is limited by the floppiness of the fabric and only mini-daisy chains. The pack’s minimalist spring steel frame is a nice conception and is comfortable to wear, but personally, I prefer a more solid structural body with obvious, durable lash points and zippered, rather than open, pockets. I received this product for free from the REI Trailblazers sampling program in exchange for my honest review.
Age:65–74
Weight:125–150 lbs.
Height:5'6"
Yes , I recommend this product
MNTRAT
PNW
Great Lightweight Backpack for Petite Sized Hikers
3 days ago
After more than 100 miles of backpacking, this pack is pretty incredible! I love how lightweight it is while still having SO many pockets that are easy to access while hiking. I tried other lightweight packs from different cottage-style brands but this one seemed to distribute the weight the most evenly for my petite from (thin on top, more average build on the bottom). I think this pack shines carrying a low base weight, but I've also had it loaded up to around 23 pounds and still very comfortably hiked 15-16 miles a day with 3,000+ ft. of elevation. I'm 5'2" and between 105-115 lbs and the XS fits perfect on me. I wish it came with the Packmod straps included in the price, but with how comfy it is, I guess it's a small downside. It's a great pack for me and I plan to use it for many more long adventures to come!
Age:25–34
Weight:100–125 lbs.
Height:5'2"
Yes , I recommend this product
Josie S
Received free product
Corvallis, Oregon
Light/durable pack great for day hikes and camping
1 year ago
I was surprised how light the pack was when I pulled it out of the box. So far, I've taken it out on a long day hike and a one-night camping trip and it did great for both. It's durable with lots of options for storing and attaching gear. I found it to be comfortable even on my first use and I was able to adjust everything to my preferences (and my body's preferences). Based on past multi-day/night trips, I think this pack is best for long day hikes (20+miles) and one-nighters.
Age:45–54
Weight:125–150 lbs.
Height:5'6"
Yes , I recommend this product
Beeeater
California
Room to improve: Outer pockets & build quality
1 year ago
Size XS (torso 16 inches, stated capacity 49L, tested with 20lb gear including water & food in bear canister): Main compartment: the capacity is lower than the Flash 55 but I was able to fit the BV450 and BV500 horizontally pretty easily; the hydration bladder sleeve is pointless – can’t use it with a bear canister and with the lower capacity inside the pack, better to use outer pockets; Outer Front Pocket: pretty low capacity, with no real give (plus the mesh weave section has such large holes it is bound to catch on something and get ripped – photo 1). Another flaw is that there is just one cord to tighten and control both the large outer pocket and the two long side pockets – you cannot independently secure the contents of each pocket. Does the ounce shaving on 2 mini cord locks and bit more cord justify this design flaw? (The two smaller lower bottle pockets have their own cord and mini cordlocks). The long side pockets have a large opening on side – another point of failure for for small objects and moisture (photo 2). That hole seems to be set up for the skimpy cord-based compression system. I could add compression straps, and mini cordlocks, cord – but that is disappointing at this price point. Hipbelt Pockets: cannot fit the iPhone Pros, ok for a bar, small snack, lip balm, headlamp; Phone Packmod is low end -just barely fits an iphone Pro but has no padding or waterproofness – so you need another aftermarket add on. Note that the overall build quality is not great: when I first put a BV450 bear can inside the pack, the outer pocket cord flew out of the last mini grommet hole situated on the underside seam of the long side pocket, likely cos the knot that secures it was loose. It was a struggle to rethread the cord and pull it out of the grommet hole and re-knot it. All the cord knots are simple overhand knots that seem prone to loosining – there is no locking mechanism or double knot. The quality of stitching was also surprisingly low – think thread nests at reinforcement points (see photo 3). Overall: I am very glad that REI is venturing into the UL pack space. There are many cottage UL pack makers out there, but there aren’t a lot of good choices for petite women (<100lb, 16 inch torso or less). Finding and testing all the options via mail order is a slow and frustrating experience. The overall fit and carry on this pack was pretty decent for me so I hope REI continues to improve it: fix the outer pockets – increase the capacity of the main outer pocket, fix the cord issue, get rid of the mesh or choose a finer mesh (think circuit); improve the pack compression or include packmod compression straps; and do more quality control on stitching and cord knots!
Weight:Less than 100 lbs.
Height:5'0"
No, I do not recommend this product
Anne_415
Received free product
San Francisco
Lightweight with structure, nice padded hipbelt
1 year ago
This bag is definitely lightweight due to fabric being this smooth UHMWPE fabric - it feels like a thin nylon wind/water resist running jacket that I own - but I haven't tested it out in rainy weather and would likely want to wrap the bag in an actual rain cover for extra protection anyway because that's just my personal preference. The carry straps, hipbelt and ventilated back panel are the elements that add the most bulk and weight to this bag. The thickness and substantial padding of the hipbelt makes me feel like it will do a good job at both lifting the weight off my shoulders (if this bag feels too heavy, to relieve my shoulders) while not cutting into my waist or constricting my stomach area too much. I typically wear between size 25-27 in jeans and the bag is pretty high-waisted on me, but of corse you can adjust where it sits on your body with the shoulder straps. There's an elastic that runs through the top of the outside pockets which you can pull to cinch in to adjust the opening and secure the items in the pockets. Think of it similar to how your hoodie jacket might have a similar cinch to pull it tight over your head. However I think this design might be fiddly because it's one long elastic running through the circumference of the bag. I think the potential risk here is if you break it, it renders the cinching useless. My guess is the designers chose to use one entire elastic band to save on weight and bulk. I can use the pull in the front to tighten the whole bag with one hand, but the risk is I can't individually adjust each of the storage sections on the outside so it depends on how you want to load and take items out. Lastly, I do wish I was able take out the back panel that keeps the pack rigid in case I ever wanted to throw this bag into my washing machine to wash... that is unfortunately not removable.
Weight:100–125 lbs.
Height:5'3"
almk
Received free product
Tucson, AZ
I'm Seriously Impressed
1 year ago
I was a bit wary of an REI product that was so lightweight. Ultralight backpacking packs are hard to make well, but this was a goodie. Keep in mind that this review is from the perspective of AN ULTRALIGHT BACKPACKER (if you aren't looking for an ultra lightweight pack, this is not the pack for you. There are better mid-weight packs out there that will make you happier. If you load too much heavy stuff in this pack, you'll hate it). Here are my favorite aspects of the pack after a full 3 day trip: 1) it's huge (for a lightweight pack). Most ultra-lightweight packs are small and lightweight. I hate that. It becomes hard to load up and you end up wrestling with the lightweight fabric trying to jam all your stuff into it. I like having extra space that I can then cinch down. For my 3 day trip, I was able to easily fit: 15 degree down sleeping bag, extra long sleeping pad, 2 person tent and poles, jetboil, accessories (such as headlamp, batteries, charging block, cords, water filter...etc), down jacket, raincoat, and my sit pad. There was still plenty of space for other things. My particular trip didn't require a bear canister, so I was able to put all my food in a bag and I hung it on a tree to keep it away from critters. However, you could easily fit a single person bear canister inside the pack if necessary. 2) it's comfortable. If you don't overload this thing (again, it's an ultralight pack and not intended to be loaded with non-lightweight gear) it's an extremely comfortable carry. The padding is nice and there's some space between the back panel and your sweaty back. That is unique for a pack like this! There's an actual internal frame to it, unlike other similar packs that don't have an internal frame. 3) features are minimal, yet sufficient. Ultralight packs are intended to be minimal. There is no top brain, and only one outer stuff pocket (which also cinches down). I found that plenty sufficient for my needs. The cinch straps are easy to understand and operate, making it easy to use. The top cinch strap is removable, but I used it for my sit pad since I wanted quick access to it and it also helped compact my gear even more for an easier carry. The water bottle pockets are amazing. I love them. They're great, just believe me. Also, the hip belt pockets are big enough for snacks or small accessories. Trekking pole attachment is minimal, but functional. There is a sternum strap whistle. Thing to pay attention to before you purchase: 1) Be sure to look at the sizing. This pack does not have adjustable torso length, so your only adjustments are in the shoulder straps, load lifters, sternum strap, and hip belt. I'm 6 foot, with an 18 inch torso length and the medium fit great. Oh, and another small feature that I didn't realize I ever needed: the sternum strap does not have a blocking stitch when you slide it up and down. It is fully adjustable vertically without the need to remove a clasp. This is perfect for adapting to different breast sizes. I appreciated this. 2) do you like using water bladders or water bottles? I'm a water bottle gal, but there is an internal hook for a bladder. However, it looked to be a pain to operate as the internal sleeve also seems to house the internal frame. I'm willing to bet you will struggle with putting a bladder inside, especially with a full pack. Overall, I liked it a lot. I would recommend this to anyone looking for an ultralight backpacking pack.
Age:25–34
Weight:125–150 lbs.
Height:6'0"
Yes , I recommend this product
camiv96
Received free product
Seattle, WA
Exceptional comfort, performance of features is eh
1 year ago
Pros: • This pack is SUPERBLY light! • The back panel on this pack is flexible but provides great support nonetheless; additionally, there is space for air flow to reduce sweat accumulation. • The foam making up the back, shoulder, and hip pads is nice and sturdy and provides real support – they essentially mold to your shape without collapsing, but aren’t so stiff that they’re uncomfortable. • The pack still has an internal metal frame that’s surprisingly rigid but doesn’t seem to get in your way or rub, even for me who has a short torso (and frequently runs into that problem). • The hip belt pocket(s) are large enough for an iPhone, zippers are easy to open/close with one hand while you’re hiking. • The straps on the pack are highly adjustable, including the chest strap (which is always a hot spot for me when backpacking) and the tilt of the pack towards your shoulders. Definitely helpful for re-distributing the weight as needed. • The pack is pretty adjustable for volume, with a large adjustable stuff sack on the front of the pack and roll-top style body. There are compression straps (albeit flimsy.. mentioned later in this review). • The fabric seems relatively rip resistant. It also seems at least water resistant if not waterproof; the interior lining has a sort of plastic coating that works (to an extent…) like a dry bag. Wouldn’t be fully waterproof in a full on rainstorm. Cons: - The aesthetic of this pack is only what I can describe as “clunky.” - It doesn’t necessarily come in the most exciting or noticeable colors; whether you’re interested in it being cute or genuinely concerned about being visible in the wilderness. The “granite blue” is really just a cooler grey color. - The compression straps don’t do a stellar job, and the pack doesn’t compress down (for smaller trips) as well as you would hope. The compression straps don’t work very well to compress the lower half of the pack (as you can see in the photos). - The only way to access the internal part of the pack is through the roll-top. - You can only access the hydration bladder pocket from the inside, which makes it hard to efficiently refill and store water when you’re on a backpacking trip. - Similarly, the side pockets aren’t adjustable and therefore don’t hold water bottles well if you prefer to carry them in a way you can grab while hiking. Overall it seems like a solid alternative for much more expensive, brand-name packs – but with some definite sacrifices in quality/experience.
Age:25–34
Weight:125–150 lbs.
Height:5'3"
No, I do not recommend this product
Kar H
Received free product
Richmond, VA
Excellent for Hiking
2 years ago
I'm really happy with this pack, it adjusts well to fit your form and has cinch cords so that you can compress it if you're not utilizing it to full capacity. I used it for 7- 8 mile day hikes so I was able to roll the top opening down and secure it with cords and clips that were easy to handle. I'm looking forward to packing it to full potential on an overnight trip in the spring! The foam in the back has a layer of mesh that extends around on the waist strap & it's very comfortable.The (removable) cell phone pocket on the front is super handy! Also great are plenty of inside and outside zipper pockets that are convenient to access, the velcro key fob inside, and grey color!
Age:55–64
Yes , I recommend this product
NJS
Broke
1 year ago
Great pack and super comfy, until the strap snapped on my second hike. 😕 REI says I’ll need to get it repaired myself, since I’m not the purchaser and I don’t have the receipt. The pack was brand new.
Age:45–54
Weight:150–175 lbs.
Height:5'6"
No, I do not recommend this product
Sunny
Received free product
Seaside, CA
Light as a feather and functional
1 year ago
This pack is so light that when the box was delivered, I thought it was empty! I volunteer for a search and rescue team and have a larger backpack for our missions. I wanted a smaller pack for shorter/simpler missions where I don’t need to carry as much equipment. Upon receiving this pack, I immediately decided that this is exactly what I had in mind. It is now my designated SAR pack. I have taken it on several test drives on hikes between 5-9 miles with about 20 – 25 pounds of weight in it. So far, the pack has performed well, handled the weight, and feels comfortable, at least for day hikes and short weekend excursions. I don’t know if I would take this on a trip longer than a weekend because I am not sure this type of frame will be comfortable for longer trips, but I can’t say for sure until I try it. The main compartment is roomy and fits more than it initially may look. I really like the roll-top lid and compression straps that allow you to adjust the internal volume of the pack. There are plenty of side pockets that are of good size and capacity. They hold my water bottle well and I can reach it without having to take off the pack. I like the removable pocket on the shoulder strap. It fits my phone perfectly. I wish the pockets on the hip belt were a little bigger as I utilize those pockets a lot. They hold a few small things, but not everything I normally like to have accessible, but that may be just me. What I like the most is that my helmet fits in the large front pocket and it doesn’t have to dangle while strapped on the outside of the pack. I’m 5’2”, 125lbs, and the size small fits me perfectly.
Age:35–44
Weight:100–125 lbs.
Height:5'2"
Yes , I recommend this product
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