Osprey Seral 4 Hydration Pack Off-The-Back Hydration Whether you're riding your mountain bike, running, or hiking, you should carry plenty of water with you. Having a hydration belt will let you carry an ample amount of water without having to carry a backpack. The Osprey Seral 4 Hydration Pack is a lumbar pack that has a 1. 5-liter reservoir with a magnetic bite valve that attaches to the hipbelt for easy access. It features an Air Scape backpanel with a contouring lumbar wrap that provides maximum stability, a large zippered main compartment with a reservoir sleeve, dual-zippered hipbelt pockets, and a zippered front pocket with internal tool organization. Features Osprey Hydraulics 1. 5L lumbar reservoir with a magnetic bite valve attachment Large zippered main compartment with a reservoir sleeve Zippered front pocket with internal tool organization Blinker light attachment with reflective graphic SPECIFICATIONSHydration Capacity1. 5LBPA/BPS/BPF Free Yes Gear Capacity4LPack Weight0. 932 LBSDimensions7. 5 x 12. 5 x 4. 5"Fits Torso-Fits Waist/Hips-Accessories Included Bike Tool Organizer, Magnetic Bite Valve Attachment Number Of Exterior Pockets- | Osprey | Seral 4 Postal | Blue | Os Hydration Pack