How to Choose Sleeping Bags for Backpacking
Sea to Summit Spark 45F Down Sleeping Bag
$349.00 – to $379.00
Count on a great night's sleep while counting grams with the Sea to Summit Spark 45F sleeping bag. It's warmed with 850+ fill-power down, and the 10-denier shell sheds wind and condensation.
Key Details
Fill
850+ fill-power goose down
Weight
Regular: 12.8 ounces
Long: 13.7 ounces
Compressed Volume
Regular: 2.4 liters
Long: 2.9 liters
Temperature Rating (F)
45 degrees (F)
- RDS-certified, 850+ fill-power goose down with a non-PFAS Ultra-Dry Down treatment for maximum thermal performance
- 10-denier shell with a non-PFAS durable water repellent (DWR) keeps the hood and footbox highly water-resistant
- Ultralight, breathable 10-denier nylon liner
- Constructed with a technical hood and zipper draft tube to retain warmth
- Technical hood, anatomic footbox and an ergonomic mummy shape—ultralight doesn't have to mean ultratight
- Sewn-through baffle construction for lighter weight
- YKK #5 zipper with zipper plow provides reliable, snag-free operation
- Half-length zipper for ultralight packability
- Sea to Summit Guarantee is offered for the lifetime of this product
Imported.
Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.
Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
View all Sea to Summit Backpacking Sleeping BagsEach bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
| Best Use | Backpacking |
|---|---|
| Tested Lower Limit | 45 degrees (F) - ISO |
| Tested Comfort | 51 degrees (F) - ISO |
| Temperature Rating (F) | 45 degrees (F) |
| Temperature Rating (C) | 7 degrees (C) |
| Weight | Regular: 12.8 ounces Long: 13.7 ounces |
| Ultralight | Yes |
| Shell | 10-denier nylon |
| Zipper Location | Left |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 850+ fill-power goose down |
| Fill Weight | Regular: 5.3 ounces Long: 6.1 ounces |
| Sleeping Capacity | 1-person |
| Lining | 10-denier nylon |
| Sleeping Bag Shape | Mummy |
| Fits Up To (in.) | Regular: 73 inches Long: 78 inches |
| Shoulder Girth (in.) | Regular: 61 inches Long: 65 inches |
| Hip Girth (in.) | Regular: 61 inches Long: 65 inches |
| Stuff Sack Volume | Regular: 2 liters Long: 3 liters |
| Compressed Volume | Regular: 2.4 liters Long: 2.9 liters |
| Gender | Unisex |
| Sustainability | Down certified to the Responsible Down Standard (RDS) |
Buying Advice
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Customer Images
katchf392f530
So comfy and warm
1 year ago
[This review was collected as part of a promotion.] This is definitely an investment in a quality sleeping bag for camping. The down material keeps you warm and snugged in temperatures that can drop overnight. It can me packed up nicely, lightweight and does not take up much space. It is very roomy, I am petite, female and 160 lbs, it zips up easily and does not snag. It is like cocoon shaped and air does not good to keep you warm. I amazed by the quality and craftsmanship. It is extremely soft and so comfortable. You have to remember the key is quality, comfort, comfort and warmth. In addition to being light weight so you can transport easily.
Originally posted on influenster.com
maddieedb23
Perfect for my light hiking/camping use!
1 year ago
[This review was collected as part of a promotion.] This sleeping bag is high quality! You can tell Sea to Summit has really spent time to get it right. I was surprised how big of a case it came in but, was happy to note that a more compact bag was included and it does shrink down easily. They are not joking when they say you will be comfortable down to 0F. As a 5’2 female, I have more than enough room to get cozy but not too much that there I do not feel snug. There are so many great features like the pillows near the hood for support, clasps to ensure much of your face is protected and the ability to zip two together. Would for sure recommend to my other outdoorsy friends. I would say this is not “over”engineered but perfect for my use. This ensures it is not too heavy to take with me on my trips.
Originally posted on influenster.com
editap1
Such high quality
1 year ago
[This review was collected as part of a promotion.] This sleeping bag is the best that I’ve ever tried. It is very lightweight but super warm. I like how easy it is to pack it up. It fits nicely in its own carrying bag, but it can be pressed even more to fit it in an even smaller space. There’s plenty of room inside, but it is not so big that it wouldn’t function properly. It is very comfortable and easy to zip into it. Even my dog was obsessed with it when I first unpacked it 
Originally posted on influenster.com
heatherw539
Buy it immediately
1 year ago
[This review was collected as part of a promotion.] This sleeping bag is amazing! It is extremely warm and will keep you toasty on those cold nights outdoors. It fit me perfect with some extra room with a height of 5ft. It is on the larger side and they give a small bag to pack it in which is very difficult to get it in. They also include testing results on the down goose and duck feathers they use to insulate it. Definitely worth the buy!
Originally posted on influenster.com
candiss4
Light & small, but performs great
1 year ago
[This review was collected as part of a promotion.] I am so impressed how light this sleeping bag is, but still keeps me warm! Compresses down without a problem - perfect companion for a backpacker/hiker. Love the attention to detail with the zipper - did not have any issues with snagging. Camped on a lake island with temps getting in the low 40s and still was comfortably warm. Material is easy to clean and shake out. 10/10 recommend.
Originally posted on influenster.com
bigheadd
So freaking cozy
1 year ago
[This review was collected as part of a promotion.] I’m so ready for a camping trip. I just can’t wait to use my new spark down sleeping bag for women by sea to summit. It’s the most snuggly sleeping bag I’ve ever experienced. It has such a soft down insulation that will keep me warm in 15 degrees. I especially like the quilt lock to keep everything in place! I so very highly recommend to all females that love to camp.
Originally posted on influenster.com
aprilsxtn83
Most Luxurious, Comfortable, Lightweight Material I Have Ever Felt!
1 year ago
[This review was collected as part of a promotion.] As an avid hiker/backpacker, I have been wanting a sleeping bag that is super light to not weigh me down and small enough to not add too much bulk on my back. I have only heard good things from the Sea to Summit brand, so I was excited to try the 30-degree Spark Down Sleeping Bag. It came with a storage bag, a smaller compression bag, a clip, and a down certification paper with tons of interesting information about the down filling. It's amazing how compressed this sleeping bag can get, and it is so super lightweight! It didn't feel like any added weight at all when attached to my backpack! It zips down about halfway, so I had plenty of room to get in it. The zipper is smooth and seems very high quality. It is a mummy style bag, so it's meant to be snug in the footboard area. However, I had plenty of room for my feet and legs to move around. I was afraid it would feel too restrictive for my liking, but that wasn't the case at all. I could move my legs to be about shoulder width apart. The hood cinches, which helps with warmth as well. For context, I am a 5 ft 5 in female that weighs 135 pounds, so I can see this working for a variety of people given how much extra room I had. As far as comfort, I can't even describe how pleasant this bag feels. My words when I first got in was, "Wow, this feels like liquid gold surrounding my body!" That's the only words that came to mind, but it's the best feeling material I have ever felt! It's truly amazing and makes me want to use it in my bed every night! Even though it's extremely soft, it also seems like a high-quality shell that will withstand several seasons of camping. As far as warmth, I took it outside on a cold night, about 35 degrees, just to test it out. I was still warm after quite a few minutes, so I think the 30-degree rating is spot on. Overall, I am extremely happy with this sleeping bag and totally recommend it to anyone looking to prioritize comfort, warmth, and lightweight material!
Originally posted on influenster.com
gotthatfireinmysoul
💕 this sleeping bag!
1 year ago
[This review was collected as part of a promotion.] I'll start off by saying this sleeping bag from Spark Down is the lightest sleeping bag I've felt/had. It easily rolls up and fits in the nylon bag it came with. The only downfall I see with the bag is the zipper. Should be larger in size. . I will say, when I pulled out the sleeping bag, it looked dirty. We thought it was previously used, but it was the down feathers that peaked through the translucent yellow material. . We haven't used it in the cold just yet, but after reading reviews, but confident it'll keep us warm.
Originally posted on influenster.com
daniela172
This bag is amazing!
1 year ago
[This review was collected as part of a promotion.] I’ve slept in my share of sleeping bags to include my cold weather issued sleeping bag in the Marine Corps almost 30 years ago. The spark Down bag is amazing. To begin, I couldn’t believe how lightweight it is. It’ll be a breeze to add this to any pack. The yellow and grey color is very attractive and looks modern and high tech compared to anything I’ve used before. The sleeping bag rolls up right into it’s nice zippered carrying case with one side of mesh to allow air circulation. The bag even included a test report to show a detailed list of its contents. I’m quite impressed with the quality so far. I’m certainly going to be visiting their site to shop for other outdoor gear.
Originally posted on influenster.com
zahrawins
High end experience!
1 year ago
[This review was collected as part of a promotion.] This sleeping bag is INCREDIBLY comfortable! It’s made of down goose feathers and high end. This is the first sleeping bag made for women that adequately hugged my curves and gave me a good night sleep. I packed it up with minutes and was ready to go back on my hike! Entirely worth its price point!
Originally posted on influenster.com
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