The Crux AK-47X is a extremely tough but lightweight 45ish liter sack for alpine use. Average weight is 1,150g!. This pack has a Cordura/Kevlar body with a double Cordura base. Lots of sensible features including a very light internal frame, side compression straps, ski carrying loops, wand pockets, large lid pocket with key fob, internal lid pocket, axe elastics and gear loop attachment points on the waist belt. All the seams are hot taped to be totally waterproof both on the main pack body and the lid. This pack comes in 3 sizes: size 1 fits 17.5 in / 45 cm back, size 2 fits 19.5 in / 50 cm back, and size 3 fits 21.5 in / 55 cm back.