Don't panic you didn't forget to pack a sleeping bag. The Marmot Plasma 30 Sleeping Bag is just so compact and lightweight that it may feel like you left it at home. It's not designed for Arctic expeditions, but for summer and moderate shoulder season trips its super high loft 875 fill down will keep you plenty warm without slowing you down or taking up space in your pack. The insulation's also been treated with Down Defender to improve its water resistance, and the tough but ultralight Pertex Quantum shell has internal and external DWR coatings as well, to shed water and keep your down as fluffy as the day you bought it. It would be tough to make a bag with a traditional design this light, but the Plasma uses Insotect Flow vertical baffles, which help direct heat to the wrap around footbox, keeping your toes warm without the need for extra down. Leaking and drafts are minimized, too, with help from the insulated draft tube, collar, and face muff, so you don't have to deal with cold air sneaking into your bag and ruining your night.