22L / 44L Expandable Cargo Pack The Rambler backpack features a water-resistant main compartment which can be used in either "roll-top" mode, or in the traditional "flap-down" configuration. A key feature of the Rambler backpack is it's ability to quickly double in size from 1,350 cu.in. to 2,700 cu.in. when needed for extra cargo carrying capacity. The Rambler also features multiple weatherproof compartments, urethane coated zippers, waterproof materials, and a carbon fiber reinforced internal frame suspension system. Front zippered pocket fits most 13in laptop computers or any tablet, a 17in laptop can fit in the rear rolltop compartment. Shoulder straps are equipped with two Arkiv rails for attachment of additional accessories. Made in the USA with a lifetime warranty.