Traverse Synthetic Sleeping Bag (25°F & 15°F)
Highlights
BEST USE: Backpacking
PERFORMANCE: 2.5 Season
WEIGHT: 2lbs 7.9oz | 1130g
COMPRESSED VOLUME: 7.3 liters
LOWER TEMP RATING: 25ºF | -4ºC
Shipping & Returns
Our warehouse is actively shipping orders from 8am to 1pm MST Monday through Friday. Most orders ship in one business day, but the transit time can take up to 7 days, depending on your distance from Boulder, Colorado.
2nd Day and Next Day Air orders will ship same day if placed by 1pm MST, Monday-Friday (except holidays).
All orders are eligible for fast and easy returns within 60 days of purchase.
For more details, please check out our Help Center
Find Locally
The EN Rating scale is a scientific test to determine the warmth of a sleeping bag. The test produces a Lower rating (for male sleepers) and a Comfort rating (for female sleepers). Both are listed in the features table on the product page.
A unisex sleeping bag with a Lower limit of 14ºF means a man should be comfortable down to air temperatures of 14ºF. The same bag will also have a Comfort limit, in the realm of 27°F, so a woman would be comfortable down to an air temperature of 27ºF. These ratings require a sleeping mat with an R-Value appropriate for expected ground temperatures – without this, the sleeping bag itself is unlikely to keep the sleeper warm enough.
A variety of factors impact sleeping bag warmth - the above temperatures are merely guidelines, not guarantees. It’s important to think of a sleeping bag, an appropriately insulating sleeping pad and a liner as a sleep system. For example - if you plan on sleeping in nighttime air temperatures of 27ºF / -3°C, choose a bag with a gender-appropriate rating of 23°F / -5°C, plus a sleeping mat with an R-Value of 2.5 to 3, and consider a Reactor thermal liner.


Description
The Traverse transitions easily into warmer weather with a full-length left-side zipper, a half-length right-side zipper, and a foot box zipper that provide unparalleled ventilation or allow the Traverse to be opened completely flat like a comforter. In colder weather, the unique WaveLoft construction allows the Thermolite insulation to expand out into air-trapping curves for maximum warmth.
Whatever the season, the wider mummy cut of the Traverse gives you room to move, no matter what position you sleep in.

Design Details
TECHNICAL FEATURES

WaveLoft™ is a unique construction technology designed to maximize loft and minimalize insulation weight. Instead of conventional flat layers of insulation (sewn flat on top of each other) or shingle layers (sewn in diagonally overlapping layers), WaveLoft™ creates curved layers which expand out from the shell to trap the greatest amount of air possible at a lower overall weight than existing synthetic insulation constructions. WaveLoft™ is used on all Sea to Summit synthetic-insulated sleeping bags, regardless of price level.

Thermolite® HL-1 is part of the family of Thermolite® materials used in Sea to Summit sleeping bags, sleeping bag liners and sleeping mats. HL-1 high loft insulation is a fiberfill constructed with a unique 3D crimp of hollow-core and solid fibers, which provides excellent lightweight warmth with superior durability. The Thermolite insulation lofts up inside the Air Sprung Cells™ of our sleeping mats to prevent convective heat loss from your warm body to the cold ground.

Down and synthetic bags identified with our zip coupling symbol use a 65 inch #5 YKK full-length zip which allows a unisex left-handed and women's specific right-handed bag to pair together. Designed to pair side by side, each person sleeps in their own bag enabling each of you to take advantage of your bag's unique insulation zones, hood and footbox features - perfect for cozy adventures for two. Bags with full-length #5 YKK zips on both sides can also be coupled together with other pairing bags.

Our Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it's not. The half-zip on the right side of the bag (left side on women's bags) provides freedom of movement for both arms, additional ventilation and allows the top third of the bag to be folded down as a mini quilt when the mercury climbs higher than expected.

Sea to Summit hydrophobic down and DWR finishes are Non-PFC.
UltraDry Down:
The down is RDS-certified responsibly sourced. The non-PFC Ultra-Dry Down™ hydrophobic treatment means it absorbs less water than untreated down and dries much more quickly. Ultra-Dry Down does not affect the loft or lifespan of the down, or its breathability. The treatment will last through at least 20 washings
Non-PFC DWR Shell fabric:
Despite being incredibly lightweight, the 10 Denier UL Nylon is down-proof and surprisingly durable. A non-PFC DWR finish helps the shell to shed external moisture. This fabric is part of the secret to making the Spark and Flame Down Sleeping Bags and the Ember Quilt Series some of the lightest, most packable sleep system products available today.
Tech specs
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Best UseBackpacking
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Comes With70D Nylon Compression Sack
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InsulationPolyester (using WaveLoft™ construction)
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ShapeMummy
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Shell FabricDurable 30D DWR Nylon shell
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Zip OptionsMain side zip and foot box zip provide superior ventilation and allow the bag to be used as a comforter.
25°F Regular | 25°F Long | 15°F Regular | 15°F Long |
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Frequently Asked questions
Is this sleeping bag warm enough for cool-weather camping or travel?
Absolutely. This sleeping bag features Thermolite® insulation with WaveLoft designed to keep you warm when the temperature drops. For colder temperatures, we recommend the Traverse 15°F sleeping bag paired with a sleeping pad that has an R-Value of 4.5 or higher, like the Comfort Light Insulated.
Is this sleeping bag suitable for warm weather and summer temperatures?
Yes, this sleeping bag is great for warm-weather camping. It features a full-length side zipper, second half-length zipper, and a foot box zipper for ventilation or to transform into a lightweight comforter.
Can this sleeping bag be zipped to another sleeping bag?
Yes! This sleeping bag can be zipped together with our Altitude, Journey, or Venture sleeping bag models. Traverse's regular and long sizes have the same side zipper length.