Western Mountaineering UltraLite Sleeping Bag: 20F Down Royal Blue, 5ft 6in/Left Zip

What Our Gearhead(R) Experts Are Saying:"The Western Mountaineering UltraLite is the bag I recommend when someone wants the best sleeping bag they can carry without feeling it in the pack.

At under two pounds for a 20F mummy, the weight-to-warmth ratio is genuinely hard to beat, and the 850-fill down compresses into a 7 x 13 inch stuff sack that disappears in a pack.

The ExtremeLite shell breathes well enough that warmer nights stay comfortable, and the nylon taffeta lining feels noticeably softer than most bags at this weight class.

It's a serious piece of kit."Some gear earns a permanent spot in the rotation and never leaves it.

Western Mountaineering's UltraLite Sleeping Bag is that kind of piece - a 20F mummy bag that weighs under two pounds and stuffs into a package small enough to wonder if something is missing.

Nothing is missing.

A full pound of 850-fill down delivers the loft and warmth that makes this bag a legitimate four-season companion for three-season conditions.

The ExtremeLite shell combines a high thread count with real breathability, so the bag stays comfortable on milder nights without sacrificing durability over a long life on trail.

The nylon taffeta lining is genuinely soft against skin after a hard day, and the down-filled collar and interlocking draft tubes lock in warmth at the points where most bags give it back.

The mummy cut runs slightly narrower through the shoulders to maximize heat retention without feeling restrictive.

It comes in three lengths to fit backpackers up to 6 feet 6 inches, stuffs to 7 x 13 inches, and earns its place at the top of the category every time someone picks it up and wonders how it can possibly be this light.