Description of Black Diamond Quantum 55L Backpack The ultimate blend of light weight and load-carrying ability in a technical alpine pack, the Black Diamond Quantum 55L Backpack comfortably hauls heavy loads using our new fully modular V-Flex suspension system that conforms to your back. A cushy 15 mm foam is used in the ergonomically-curved shoulder straps and 20 millimeters in the waistbelt with an additional three millimeters of stiffer foam adds on pressure points for weight distribution. The Quantum is built with ultralight, durable and water-shedding VX 21 Dimension Polyant laminated fabric and lined with lightweight 30d SilNylon. For summit pushes, alpinists can minimize by removing the V-Flex suspension, top lid, waistbelt and crampon straps. The performance of an alpine pack and the comfort of a backpacker's pack. Lightweight, nylon-only waistbelt included. Exhaustively engineered to provide technical big-mountain function with the carrying comfort and performance of a backpacking pack. Features: VX21 Dimension Polyant fabric V-Flex suspension with dual-density shoulder straps, removable waist-belt Hydration compatible Weight: 2.26 kg (5 lb) Water-resistant Lid external pocket Top and side access Stripped Weight: 1 kg (2 lb 3 oz) Volume: 55L (3357 cu in) Torso Sized: S/M 43–51 cm (17–20 in) L/XL 51–58 cm (20–23 in)