Big Agnes Sidewinder SL 20 Sleeping Bag (650 DownTek) Long – Side Sleep Comfort

Meet the Big Agnes Sidewinder SL 20 Sleeping Bag in Long length, crafted for campers who sleep on their sides. It combines a traditional mummy silhouette with body mapped insulation to follow your curves through the night, aiming to deliver warmth where you feel it most while reducing pressure points. This isn't a promise, but a thoughtful design intended to support a comfortable, restful night on varied adventures.

Smart warmth tailored for side sleepers

The bag uses 650 fill DownTek throughout the main body to provide lofty warmth, while FireLine ECO synthetic insulation at the hips and feet helps soften common pressure points. The DownTek treatment helps preserve loft when humidity is present, and the bluesign certified water repellent finish adds durability for damp nights.

• 650-fill DownTek insulation for plush warmth and moisture resistance
• Synthetic FireLine ECO in hips and feet to reduce pressure points
• Bluesign certified water repellent finish for durable protection

Designed to move with you

The side sleeper friendly pattern, jacket style hood, and an insulated hood tube seal keep warmth close without sacrificing mobility. A long, ambidextrous zipper provides easy entry and access as you roll from side to side.

Practical features that support restful nights

• Pillow Barn secures your pillow with interior access from both sides
• Anti-snag locking zipper with no draft garage for smooth operation
• Exterior loops for hang drying or quick storage; includes storage and stuff sacks

Size, fit, and durability you can rely on

Long length accommodates up to 6'6" (198 cm) with generous shoulder and hip girths. Weighing roughly 2 lb 8 oz, it packs to about 7.5 x 8 inches. The design includes a lifetime warranty, reflecting Big Agnes confidence in durability for backcountry use.

What this means in practice

Expect a warm, lofty feel with thoughtful zones that respond to your night moves. The Sidewinder SL 20 is a versatile option for multi-night trips in variable conditions, offering warmth, comfort, and practical features without promising outcomes.