The North Face Surge II Charged Backpack Synthetic Fabric: 420D nylon, 1680D ballistics nylon Joey T55 battery pack offers up to two-and-a-half full battery charges and several days of partial charges on your cell phone, MP3 player, tablet, or other USB devices. Rugged water- and crush-resistant lithium polymer battery pack was developed specifically for outdoor adventures Dedicated lay-flat 17" laptop pocket with Neoprene tablet sleeve allows for checkpoint-friendly travel FlexVent injection-molded shoulder straps with a top layer of Atilon foam for added support and bottom layer of PE foam for added comfort