Big Agnes Sidewinder SL 35 Sleeping Bag (650 DownTek) Long – Side-Sleeper Warmth & Comfort

Sidewinder SL 35: a side-sleeper focused design

Specifically crafted for people who sleep on their sides, the Sidewinder SL 35 embraces your natural alignment with an ergonomic cut and body-mapped insulation. It moves with you as you roll from side to side, helping minimize pressure points and maintain loft where warmth matters most.

Warmth and comfort where you need it

Lofty warmth comes from 650-fill DownTek across the main body, delivering warmth and water-repellency in damp mornings or misty campsites. In the hips and feet, FireLine ECO synthetic insulation adds targeted warmth, helping reduce pressure points for a more restful night.

Smart design that supports side sleeping

A jacket-style hood fits snugly without restricting movement. An insulated tube around the hood seals out drafts, while a unique Pillow Barn holds your pillow in place with easy access from either side. The long, ambidextrous zipper stays out of your way when you switch sides.

• Body mapped insulation moves with you for fewer gaps and more consistent warmth.
• Down fill throughout balances loft with compressibility; synthetic fill concentrates warmth where you feel it most.
• Anti-snag locking zipper with no draft garage and exterior loops for hang-drying or storage.

• Pillow Barn design keeps your head supported, improving stability during restless nights.
• Ventilation remains flexible thanks to the thoughtful zipper geometry and hood draft-control.
• Designed to travel from one adventure to the next with a compact pack size.

Materials, sustainability, and durability

DownTek is water-repellent and bluesign certified for safer chemistry, while 100% post-consumer recycled polyester backs the synthetic fill. This bag is built to perform across changes in temperature and terrain, and it’s designed for campers up to six feet six inches tall.

Size, weight, and care

Weight is about 2 lb 4 oz, and it packs to roughly 6.5 by 8 inches. It ships with a storage sack and a stuff sack for flexible packing and dry storage at camp.

Warranty and reassurance

Big Agnes offers a lifetime warranty on this bag, reflecting the brand’s confidence in durable gear that accompanies you on many adventures.