McHale O-Sarc Roll Top (similar to their current S-Sarc). 23.5 inch frame size. Weight 3 pounds. 4000 cubic inches volume. 4500 with zippered flap pocket. 5000 with extension. Easily carries 35-40 pounds. Features, front kangaroo pocket. Removable and moldable aluminum frame stays. Sil-nylon drawcord top extension. Horizontal daisy chains. Removable Water bottle pouches (not shown). Removable summit flap with zip pocket. This pack is in superb condition. New this would run over $900. Will sell for $350 shipped.