Sidewinder SL Sleeping Bag: 20F Down

What Our Gearhead® Experts Are Saying:

“I have put the Big Agnes Sidewinder SL Sleeping Bag 20F through a full backpacking season and the difference from a standard mummy bag is immediately apparent the first night you spend in one as a side sleeper. The bag moves with you as you shift positions through the night rather than twisting and pulling against you, and the body-mapped synthetic insulation at the pressure points means I wake up without the stiffness that comes from sleeping on compressed down all night. The ambidextrous zipper is a small detail that matters a lot when you are getting in and out in the dark.”

Most sleeping bags were engineered around the idea that you will stay still through the night, and if you do not, the bag makes you pay for it with twisted insulation, cold spots, and a morning that feels worse than the night before. The Big Agnes Sidewinder SL Sleeping Bag 20F was built around a different assumption entirely, designed to move with the body through every position change so the insulation stays where it belongs and the sleep stays uninterrupted.

Big Agnes achieved that through a combination of 650-fill DownTek as the primary insulation and body-mapped 100% recycled synthetic insulation at the pressure points where down compresses and loses its effectiveness, delivering consistent warmth across the zones that matter most for side sleepers. The nylon ripstop face fabric and polyester taffeta lining both carry a water-repellent finish that protects the insulation from condensation and light moisture inside the tent, and the ambidextrous zipper lets you get in and out from either side without fumbling in the dark. A mesh pillow pocket adds comfort and support for riders who want a dedicated sleep setup in the backcountry, and at 2 pounds 4 ounces packing down to 8 by 17.5 inches, the Sidewinder SL carries light enough to earn its place on any overnight objective where quality sleep is part of the plan.

Details

• A 20F mummy bag engineered to move with side sleepers through the night
• 650-fill DownTek primary insulation delivers warmth down to 20 degrees
• Body-mapped recycled synthetic insulation relieves pressure points overnight
• Nylon ripstop shell and taffeta lining both carry water-repellent finish
• Ambidextrous zipper allows entry and exit from either side in the dark
• Mesh pillow pocket adds support for a dedicated backcountry sleep setup
• Packs down to 8 x 17.5in at 2lb 4oz for an easy carry on overnight trips
• Lifetime warranty backs the bag through every season of backcountry use
• Item #BAGZ2AA