The Osprey Exos 46 is the ultimate thru hike and super lightweight backpack, thanks to Osprey's AirSpeedSuspension, which teams a 6061-T6 Aluminum frame with a 3D tensioned mesh backpanel, and side crescent ventilation. The AirSpeed suspension works in tandem with the supportive and ventilated Bio-Stretch harness and hipbelt for fit and comfort unheard of in a one kilo pack. Features: Single vertical zippered front pocket. Single tool attachment