Mammut Sphere Alpine Spring

Couples camping just got a whole lot better–and lighter–with this down bag built for two.
Sphere Alpine Spring
Price $370.00


Fill Power 850
Features Hood
Weight 1 lb, 3 oz

Who says ultralight can’t be sexy? This double bag weighs little more than many single sacks in its temp category, but lets you and your sweetie share, er, warmth. “I’ve zipped bags together and tried heavier doubles,” says one tester. “This is a revelation.” The 900-fill love nest is much more than an extra-wide bag. The key innovation: Independently adjustable hoods, draft collars, and footboxes that maximize insulation in subfreezing temps.

Feathered Friends says the complex design took eight years to develop. Premium down, wispy Pertex UL fabric, and the absence of bottom insulation further reduce weight. The Spoonbill has no official rating, but our consensus: Five inches of loft and shared warmth make this a legit winter (above zero) bag. Our testers had to open the individual, two-way zippers because they found the bag too warm on a 25°F night in Arizona. Bonus: The Spoonbill fit our 6’6” tester. $800; 2 lbs. 9 oz. (reg.); two lengths; also available with 850-fill and Schoeller Nanospshere shell for $100 less; featheredfriends.comThe prolight TX(R) outer fabric of the Sphere Alpine models has a DWR coating for better protection from wind and wet conditions. Outer fabric is featherlight, windproof and water repellent. Wave shaped chambers prevent slipping of the down and stop cold spots. Polish Goose Down insulation