A friend of mine is getting ready to climb Everest so I’ve been assisting him with finding all the gear he needs.
I discovered the perfect sleeping bag for him that will keep him warm and cozy even if the temperature gets down to -50 F.
Valandre makes top of the line down sleeping bags. Their Thor sleeping bag is made specifically for high altitude expeditions, polar expeditions, and winter alpine climbing. It is filled with 850 fill mature goose down. It has 50.2 oz (1424 g) of down but only weighs 75.6 oz (2144 g). It’s compressed volume is 16 liters but it’s well worth the space in your pack.
Valandre also makes down coats, pants, and mittens so if you’re looking at buying anything down you should check out Valandre.