How to Choose Hiking Boots
REI Co-op Flash Hiking Boots - Men's
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Fly over trails in the waterproof, breathable men's REI Co-op Flash hiking boots. REI-exclusive technologies create fast-and-light boots—with a lighter footprint—that are comfy right out of the box.
Shop similar productsKey Details
Waterproof
Yes
Upper
99% recycled PET polyester FirmaKnit; 30% recycled thermoplastic urethane (TPU) overlay
Weight (Pair)
2 lbs. 2 oz.
- Strong and socklike FirmaKnit™ uppers are made from 99% recycled PET polyester and are designed for lightweight yet durable comfort right out of the box
- HydroWall™ complete waterproof/breathable protection keeps your feet dry when the trail ahead isn't—and uses 75% recycled polyester to do so
- 20% recycled rubber TerraGrip™ tread provides anti-slip grip on all kinds of terrain with 4 mm forefoot climbing lugs for going up and 4 mm heel braking lugs for coming down
- TerraLoft™ midsoles use 10% algae-based BLOOM™ foam to cradle your feet with a cushioning system that feels like your favorite trail-running shoes (soft, but not too soft)
- TrailBed™ insoles use Insite® Contoura® technology created with podiatrists to ensure support and comfort; plus, it's made with 25% USDA-certified bio-based Susterra® compound
- 2-layer 30% recycled TPU overlays are designed to create durable and supportive uppers—the structure you need for long hours on the trail that's still light and minimalist
- Molded nylon midfoot shanks provide lightweight support to protect your feet from the trail and help propel you forward
- Recycled PET polyester webbing and lacing creates a midfoot cradle system that allows for a highly adjustable and locked-down fit
- Extra space in the toe boxes allows for natural changes in your feet (like swelling) during hours of trail exploration
- Informed by feedback from over 6,000 people and field tested by 100 co-op members over 2,000 hours and 700+ miles
- 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
Imported.
View the REI Co-op Flash Product LineView all REI Co-op Men's Day Hiking Boots| Best Use | Hiking |
|---|---|
| Footwear Height | Over-the-ankle |
| Footwear Closure | Lace-up |
| Waterproof | Yes |
| Type of Waterproofing | HydroWall waterproof/breathable membrane using 75% recycled polyester |
| Upper | 99% recycled PET polyester FirmaKnit; 30% recycled thermoplastic urethane (TPU) overlay |
| Midsole | TerraLoft EVA using 10% algae-based BLOOM foam |
| Support | Molded nylon midfoot shank |
| Outsole | TerraGrip rubber (20% recycled) |
| Vegan | Yes |
| Weight (Pair) | 2 lbs. 2 oz. |
| Gender | Men's |
| Sustainability | Contains recycled materials From a Climate Label Certified brand |
REI Co-op Footwear - Men's
| 8 | 8.5 | 9 | 9.5 | 10 | 10.5 | 11 | 11.5 | 12 | 12.5 | 13 | 14 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| U.S. Men's | 8 | 8.5 | 9 | 9.5 | 10 | 10.5 | 11 | 11.5 | 12 | 12.5 | 13 | 14 |
| UK | 7 | 7.5 | 8 | 8.5 | 9 | 9.5 | 10 | 10.5 | 11 | 11.5 | 12 | 13 |
| EU | 41 | 42 | 42.5 | 43 | 44 | 44.5 | 45 | 46 | 46.5 | 47 | 48 | 49 |
Buying Advice
More expert 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
Definatelty Need to Try These On
Offshore4 years ago
I found these to have an odd fit. The toe box was wide, the midfoot was narrow, and the heel was wide. Even with a winter weight sock, my heel was slipping - so these never made it out of the house. For reference, I wear Keen, Oboz, and Merrell and have no fit issues. How a shoe fits is obviously a highly individual issue so I based my "meh" rating on a couple of other things. The first big concerns is whether these could handle rocky trails without destroying the soles . I've had shoes destroyed in 50 miles (Why hello, Oboz...) and didn't get a great sense of confidence that these would do better. Of course the only was to tell is to use them and see, knowing the REI warranty is on your side. The second issue is really wondering where the value is with this shoe. Historically, REI-branded merchandise is a great value in that you get the features and performance of the big names in gear at a more affordable price. These however are priced right among their competitors like Merrell, Keen, etc. - and at best will give the same performance, but at the same price. They may be fine, but its not like you're saving anything sticking with a private label. Still, if they fit and your trail conditions are appropriate for fairly lightly constructed footwear, they are worth a look.They aren't a game changer, though.
Offshore
NJ
43 people found this review helpful
Most Helpful Critical Review
Definatelty Need to Try These On
Offshore4 years ago
I found these to have an odd fit. The toe box was wide, the midfoot was narrow, and the heel was wide. Even with a winter weight sock, my heel was slipping - so these never made it out of the house. For reference, I wear Keen, Oboz, and Merrell and have no fit issues. How a shoe fits is obviously a highly individual issue so I based my "meh" rating on a couple of other things. The first big concerns is whether these could handle rocky trails without destroying the soles . I've had shoes destroyed in 50 miles (Why hello, Oboz...) and didn't get a great sense of confidence that these would do better. Of course the only was to tell is to use them and see, knowing the REI warranty is on your side. The second issue is really wondering where the value is with this shoe. Historically, REI-branded merchandise is a great value in that you get the features and performance of the big names in gear at a more affordable price. These however are priced right among their competitors like Merrell, Keen, etc. - and at best will give the same performance, but at the same price. They may be fine, but its not like you're saving anything sticking with a private label. Still, if they fit and your trail conditions are appropriate for fairly lightly constructed footwear, they are worth a look.They aren't a game changer, though.
Offshore
NJ
43 people found this review helpful
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Maquisaldo
Lima, PERU
NOT really waterproof, very disapointed ...
1 year ago
Ive got a pair of Flash 2 years ago and just came back from a jungle trip were they did NOT passed the waterproofing test after crosing a swampy area ... Really disapointed with them.
Age:45–54
Weight:150–175 lbs.
Height:5'9"
Typical Shoe Size:Mens 9.5
No, I do not recommend this product
Moosface
Received free product
Los Angeles, CA
Nice boots, but not waterproof & wrong fit for me.
4 years ago
After wearing these boots almost daily now for over a week, here are my notes. Build/Initial thoughts - The build quality seems really good. They're made from a lot of recycled materials and though I can't speak for their longevity, they do appear to be well made. The first thing I noticed was that they felt very lightweight; I weighed them at 18.9oz each for a size 10. The removable insole is cushy and also offers nice support with a decent arch. I typically replace insoles with SuperFeet but find no reason to here. These feel more like I'm wearing a pair of sneakers than hiking boots. Performance - Out on the trail I found the sole to have very good grip. Whether on a wet grassy hill or loose gravel on a steep rocky decline they didn't want to slip at all. I often wear a full boot over a short hiker on all but the hottest days because I like the ankle support. These are a great in-between, offering more ankle support than I expected, but feeling more like a short hiker than a big backpacking boot. They really are a great all-around boot; even a quick run felt good. Waterproofing - I tried to get out in the rain, but it stopped just as I left the house so I was only able to walk through a few shallow puddles and some wet grass. They appeared to repel the water very well and my feet were perfectly dry when I got home. In an effort to test them better I stood in the shower and sprayed them for about 5 minutes. Initially I was pleased to find my feet come out perfectly dry, but after about 30 minutes of letting them sit to dry I discovered the insole of the right boot to be drenched. This wasn't water that had come over the top (my socks were dry), but rather had seeped in slowly through the fabric after having been removed from wet conditions. This was very disappointing. I expect my non-waterproof shoes to be extremely breathable and my waterproof shoes to be waterproof. Fit - As I mentioned before these boots feel nice and cushy and are mostly very comfortable. The laces made for fast entry/exit and also allowed me to tighten with some specificity. I did find that there was some rubbing on the inside of my ankle bone on my right foot that after several days made them feel unpleasant to put them on. I think this aligned with the single D-ring style lace eyelet at the top (the rest are webbing loops). It seemed to dissipate after moving around in them for a few minutes though. My biggest issue is that the toe box is slightly too narrow for me, my baby/pinky toe gets pushed in ever so slightly and while it'd not painful it is annoying. I actually have this issue with many boots/shoes so maybe it's just my feet, but I'm always a little baffled by why boots in particular aren't designed with slightly wider toes boxes. Your feet are bound to swell on long hikes and while you need support at the heel and through the midsection to keep your foot in place there is no reason for the toebox to be narrow. It is the most common reason for a shoe to not fit me well. In summary, I think that with a compatible foot shape these boots would provide all-day comfort with exceptional grip. I would recommend any buyer that cares about them being waterproof to test them thoroughly before relying on them to keep your feet dry.
Age:35–44
Weight:125–150 lbs.
Height:5'10"
Typical Shoe Size:Mens 10
Yes , I recommend this product
Dingodawg13
Portland OREGON
Great fit!
2 years ago
Had a few boots in my time as a co-op member. Some were trail and error, others took time to settle in. These boots fit surprising well first time I put my foot in them. I’m 6’2”, 267lbs. My Feet are beat up! My size 14 sunk in these like, cradled like a baby. Soft cushion out sole they felt comfortable and very sturdy. Price was pretty good as I marveled at the fact I just got them for a steal! My boots I wear? Asolo, Lowe, Danners, never had I just placed my foot in a hiking shoe at my size and felt completely free of hot spots, lost circulation, and improper size! A 14? Unheard of! Yeah, walked them out the store, ran down the street! Not a bad thing to add! Ohh! Just one….the shoe string are horrible! Gotcha! So next day ran these up Beacon Rock state Park. Rocks, steep terrain, uneven surfaces, I had put on one pair of smartwool socks. If these where going too hold up I wanted too see how bad my feet would be when I returned from the climb. Granted Beacon rock trail in some places is paved with concrete but never the less tough on a boot. The shoe held up nicely! No hot spots, no ankle grab, a cushion feel all the way up then back down. Feet where comfortable during the whole hike! Now the Life long three season or just one…test! Doesn’t really matter too me, boot provided itself out of the box!
Age:55–64
Weight:250–275 lbs.
Height:6'2"
Typical Shoe Size:Mens 14
Yes , I recommend this product
rob75
Dublin, Ohio
Comfortable, but with 2 small issues
2 years ago
First off, these boot are very comfortable. I have a wide foot and got a wide size and it fit perfectly. The 2 issues I had with them were I did not care for the super skinny laces, so I replaced them with a thicker lace. The second and main problem I had was what others have mentioned, and that was the metal eyelet for the top lace just dug into my ankle bones. VERY uncomfortable. I fixed this by cutting the metal eyelets off and running the laced through the holes that the metal eyelets sat in. Problem solved. I would have returned them but I bought them on clearance so I was unable to, so this alteration solved the problem.
Age:45–54
Weight:225–250 lbs.
Height:5'9"
Typical Shoe Size:Mens 11
Yes , I recommend this product
french flying pig
GR20 Corsica France
did the GR20 Corsica with them
3 years ago
bought the black ones to do the GR20 in Corsica in june 2022: the hardest hiking trail in Europe. 111 miles, 40,000 ft positive elevation, 16 days. from gravel and dirt to sharp granite rocks and eternal snow. Had to tune lacing on one foot which was hurting; Had to super glue the front rock guard half way through to keep waterproofness and adhesion; sculpture worn off (as planned; it is a very hard hike); Merrel and Salomon did better (no repair); without the need for repair, overall good investment.
Age:45–54
Weight:150–175 lbs.
Height:5'7"
Typical Shoe Size:Mens 8.5
Yes , I recommend this product
mtaub
Received free product
Milwaukee, WI
Run over by multiple semis with no damage!
4 years ago
When I first got the boots I thought they were too big. After speaking with REI I was told they left them roomy to allow for your feet to swell during hiking. After wearing them with full calf socks and wearing them for a bit they did begin to fit much better. The boots have a great appearance and are solid performers on a variety of terrain. We recently took a road trip to Phoenix and stopped in the Grand Canyon and Denver on the way back. I used them while hiking in each location and had no issues whatsoever. I even wore them horseback riding! When on the highway in AZ the rooftop carrier popped open and one of my boots flew out. Before I could recover it at least 9 semi-trucks had run it over. It suffered only minor cosmetic damage and performed well in the grand canyon after.
Age:35–44
Weight:200–225 lbs.
Height:6'3"
Typical Shoe Size:Mens 11
Yes , I recommend this product
Blaze
New Jersey
Super light and comfortable out of the box
4 years ago
great boots for the price, had them for a while and finally got to take them out on a 7 mile hike, was cold, rainy, muddy and standing water on the ground. These boots performed perfectly, comfortable straight out of the box for me, extremely light for their size, tons of grip. Definitely recommend so far.
Age:35–44
Weight:125–150 lbs.
Height:5'7"
Typical Shoe Size:Mens 9
Yes , I recommend this product
Alex F
NJ
Comfortable boot, got 6-months out of the soles
2 years ago
Bought these on 50% off sale for light hiking and daily dog walking. Waterproof-ness was a plus, a the price was right. They were comfortable from day one, no break-in required for my feet, and they kept my feet dry through regular rain and wet ground conditions. Downsides: 1). Laces broke after ~3 months of wear. Easy replacement. 2). After ~6 months of semi-daily use, the front of the soles and heel pads are completely worn off flat. End result - I can no longer wear them in the rain or on damp trails, unless I want to slip'n'slide. Super disappointing durabiltiy.
Age:35–44
Weight:200–225 lbs.
Height:6'0"
Typical Shoe Size:Mens 10
No, I do not recommend this product
GM the Builder
Colorado
Sole ripped off bottom within a year.
1 year ago
Used boots for hiking and work. Sole ripped off of the bottom within a year.
Age:25–34
Weight:175–200 lbs.
Height:6'1"
Typical Shoe Size:Mens 12
No, I do not recommend this product
Anonymous
Springfield, IL
Surprisingly well thought out boots with great fea
2 years ago
First impression was 3 star, but broke-in 5. Initially the upper made some noise as I walked and it had an unnatural feel to it. After a few days they started to break-in. The upper material is recycled, and so far seems really tough. Rei really did take good features from other boots and combined them. The soles have grip, the toe area is roomy, but my foot doesn’t slide. I’ve been wearing them a lot lately and I really like them. It’s kind of amazing that these are made up of almost entirely recycled or eco friendly materials. I have a pair of Solomons I absolutely love, but these are a close second.
Age:45–54
Weight:150–175 lbs.
Height:5'6"
Typical Shoe Size:Mens 9
Yes , I recommend this product
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