Size: 20 1/2″ x 15″ x 7 3/4″ - 12 3/4″ WHEN FULLY EXTENDED; Capacity: 39~64 Liters.; Weight：2.7 lbsnConstructed of 600 denier polyester with vinyl backing. External Molle loops allow additional pockets to be attached if necessary. Extra-Large expandable main packing compartmentnMain area expands from 5u0026#34; to 10u0026#34; 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 claspsnWhether itu0026#39;s a long hike, an overnight trip, or a weekend getaway,the Expandable Backpack will fit your needsnThis 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.n08001A/ Expandable Tactical Backpack Description: Material: Heavy-duty 600D PVC · Capacity: Up to 2,470-cu. in. capacity, 40/50L capacity. · Type: Softback · Use: Camping u0026 Hiking · color: as catalog · size: 14.5" x 21" x 8" · Main area expands from 5" to 10" to fit more gear · 2 accessory pockets · Water bottle mesh pocket · 2 electronics pockets on shoulder straps · Removable waist belt · Daisy chain holds rain gear, etc. Main compartment is 19 x 13" and expands from 5" to 10" to accommodate extra vital assault gear to complete your mission. 08002B/3 Day Expandable Backpack Description: l Constructed of 600 denier polyester with vinyl backing l Large expandable main packing compartment l Organizer pocket l Side parachute clasps l Easy grip zipper pulls l Back support belt with parachute clasps l Whether it's a long hike, an overnight trip, or a weekend getaway, the Expandable Backpack will fit your needs l Extra-large, expandable main packing compartment l Easy-grip zipper pulls l Back support belt Size: 20 1/2″ x 15″ x 7 3/4″ - 12 3/4″ WHEN FULLY EXTENDED Volume: 3920 cubic inches Weight：3 lbs; 08002A/3 Day Expandable Backpack Description: l Constructed of 600 denier polyester with vinyl backing l Large expandable main packing compartment l Organizer pocket l Side parachute clasps l Easy grip zipper pulls l Back support belt with parachute clasps l Whether it's a long hike, an overnight trip, or a weekend getaway, the Expandable Backpack will fit your needs l Extra-large, expandable main packing compartment l Easy-grip zipper pulls l Back support belt Size: 20 1/2″ x 15″ x 7 3/4″ - 12 3/4″ WHEN FULLY EXTENDED Volume: 3920 cubic inches Weight：3 lbs