600D Polyester with water resistant coating Features Air Bridge system to enhance ventilation and comfortable transport Laptop padded compartment fits a 15'' laptop and a tablet. Secondary zippered pocket compartment has a basic organizer Hidden zippered pocket containing a high-viz rain cover that can detach from the pack Series of gear attachments, daisy chains and side mesh pockets Unisex sternum strap and padded waist strap are adjustable Emergency whistle is built into one of the compression straps