29-liter backpack. 600D polyester, 450D x 300D heather polyester, 600D geo emboss polyester, 1200D polyester. The FlexVent suspension system boasts custom injection-molded shoulder straps and a padded mesh back panel with a spine channel for maximum support and ventilation. Floating padded laptop sleeve in main compartment. Front elastic bungee for exterior storage. Two mesh water bottle pockets. Comfortable, padded top haul handle. Sternum strap with whistle buckle.