3 Day Expandable 39 - 64 L Outdoor Tactical Backpack Military Sport Camping Hiking Trekking Bag 08002 Size: 20 1/2 x 15 x 7 3/4  12 3/4 WHEN FULLY EXTENDED; Capacity: 39~64 Liters.; Weight2.7 lbs Constructed of 600 denier polyester with vinyl backing. External Molle loops allow additional pockets to be attached if necessary. Extra-Large expandable main packing compartment Main area expands from 5 to 10 to fit more gear.The bag with 3 compartment for different function. An Organizer pocket has several mesh compartments built in. Side parachute clasps. Easy grip zipper pulls .Back support belt with parachute clasps Whether its a long hike, an overnight trip, or a weekend getaway,the Expandable Backpack will fit your needs 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.