Size: 20 1/2″ x 15″ x 7 3/4″ - 12 3/4″ WHEN FULLY EXTENDED; Capacity: 39~64 Liters.; Weight：2.7 lbs
3 Day Expandable 39 - 64 L Outdoor Tactical Backpack Military Sport Camping Hiking Trekking Bag 08002A This backpack is designed to support all your outdoor adventure and hiking needs. It features and extra-large expendable main compartment to fit everything you need for a day hike, overnight or three trip. It can be compressed to 39 liters or expanded to 64 liters of carrying space. Side parachure claps allow for tightening to provide a compact , easy to transport pack.