Really warm down pants, it doesn't hurt when it's freezing cold. You don't need to wear woolen pants underneath. I highly recommend.
Verified buyer

Jack Wolfskin Atmosphere Down Pants - Men’s highly packable, light down pants, perfect for mobile life in cold climates! With the bulk of insulation made with down, and synthetic insulation at the seat and knees these really take the bite out of winter days! Syntethic insulation is used on the lower legs, knees and seat instead of down. The syntethic fibre is less sensitive to moisture than down.
Weight refers to size L.
It is highly advisable to store the pants at home outside their packing bag.