Texsport Medina 2 Liter Hydration Water Pack for Outdoor Biking Hiking Camping Survival Backpack Constructed of durable, lightweight polyester with rip-stop body panel Main compartment holds 2 liter water bladder and front zippered accessory pocket Elastic drawstring for securing items; Front and back reflective strips for safety Adjustable stay-cool mesh shoulder straps and sternum strap with quick release buckle Padded back for extra comfort; Includes 2 liter water bladder with locking bite valve