Description of Seal Line Urban Backpack - Large This unique roll-top backpack made of PVC-free 600D PU-coated polyester and scrim-reinforced urethane provides watertight protection around town and on the trail. It includes an innovative QuickClip closure for easy, one-handed fastening/unfastening, as well as Seal Line's Modular Accessory Pocket system for attaching add-ons, such as a Zip Pocket™ or Mobile Electronic Case™ . Other key features include breathable, ergonomic shoulder straps that combine with a sternum strap and hideaway waist belt for a comfortable, supportive fit; a breathable, waterproof back panel; and an external pocket and carry handle. Features: PVC-free 600D PU-coated polyester Scrim-reinforced urethane QuickClip closure Modular Accessory Pocket Breathable, ergonomic shoulder strap Sternum strap Hideaway waist belt Breathable, waterproof back panel External pocket Carry handle Weight: 2lbs. (907 g) 2270 cu. in. (37 liters) 10 x 14.5 x 23 in. (25 x 35.5 x 58 cm)