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  • Fully zipped, the Basecamp Bt3 will keep you warm down to 25°F; for warmer nights unzip the bag on one or both sides for cooling ventilation
  • The top layer can be completely removed for use as a quilt, or use the top by itself with a sleeping pad for an ultralight sleep system
  • 2-layer offset construction uses high-quality Thermolite® synthetic insulation for maximum loft and warmth
  • Sleeping pad (sold separately) slides into a pocket at the foot of the bag and secures with a loop strap
  • The foot of the Basecamp can be unzipped for ventilation and has a roomy footbox that holds its shape, even when unzipped as a quilt
  • Aeros pillow (sold separately) secures in place with an elastic strap under the insulated hood


Many sleeping bags are rated for temperature by an independent testing protocol, the European Norm (EN) 13537. Each bag gets two ratings: a Comfort rating and Lower Limit rating. The Comfort rating is the lowest temperature at which the bag will keep the average woman (or "cold sleeper") comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep an average man (or "warm sleeper") comfortable. Everyone's body and sleep comfort is different, so EN Ratings are merely a guideline to help you compare products.

View all Sea to Summit Men's Sleeping Bags

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Best Use Camping
EN Lower Limit 25 degrees Fahrenheit
EN Comfort 35 degrees Fahrenheit
Temperature Rating (F) 25 degrees Fahrenheit
Temperature Rating (C) -4 degrees Celsius
4 lbs. 1 oz.
3 lbs. 8 oz.
Shell 30-denier nylon taffeta
Zipper Location Left/Right
Insulation Type Synthetic
Fill Thermolite
Lining 50-denier polyester
Sleeping Bag Shape Semirectangular
Fits Up To (in.)
77 inches
72 inches
Shoulder Girth (in.)
82 inches
77 inches
Hip Girth (in.)
81 inches
75 inches
Stuff Sack Size
9 x 20 inches
8 x 18 inches
Stuff Sack Volume
20 liters
15 liters
Compressed Volume
12.8 liters
11.6 liters
Gender Unisex
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Will this bag accommodate a 25" wide (x 4") sleeping pad into the pocket and loop straps?

Asked by: Drtgrl
According to the vendor, this sleeping bag has been tested with a 25" wide sleeping pad that is 2.5" thick. However, they note the straps can accommodate a thicker 4" pad with a little bit of effort.
Answered by: REIservice
Date published: 2017-04-25

Can two of these, one regular, one large, be zipped together? despite left and right zippers it isn't clear if this will work for this bag.

Asked by: pombear
​Two of these sleeping bags can be zipped together.
Answered by: REIservice
Date published: 2017-05-11
  • y_2017, m_6, d_23, h_15CST
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