Stay warm while at base camp in the men's Rab Argon Down Pants. It's filled with light , compressible and ultra-warm down insulation which will keep your lower half toasty after the sun goes down in the high mountains. Easy but durable Pertex Endurance fabric protects against light waves and rain. from unexpected weather. Goose down with its outstanding warmth-to-weight ratio keeps you comfortable without weighing you down, but treated with Nikwax's fluorocarbon-free formula therefore it keeps warm even if it gets a little wet. Besides the down is made from geese that have never been plucked or force-fed therefore it can be worn with a clear conscience.