Backpack Stone 45. When your cragging outings call for sleek and hassle-free performance, the Black Diamond Stone 45's removable top lid and full-length side zip blend easy access with functionality. With recycled fabrics in the body construction, the Stone 45 pack’s 45-liter capacity allows for organization in the alpine or at the crag. Tuck-away ice-axe loops and a rope strap keep your gear sorted and compression straps lock down extra equipment.