Awesome backpack - just moving on from the sport. 63L bag, with 2100 cubic inch main compartment, front and two side pockets, and extension collar. Carbon fiber hoop to provide support and 1/4inch foam back pad. Unlike many ultralight bags, this one does have load lifters. Made of 400 denier Robic. Water resistant and VERY hard wearing. I used a different Ohm for many miles before replacing with this bag, but am moving on. Very lightly worn.