CamelBak RaceBak Men's Hydration Shirt Vest design offers maximum mobility and comfort under any jersey. Pouch holds a CamelBak 72 oz. reservoir firmly on your back Chafe-Free flat seam stitching eliminates abrasion along seams. Full zip makes it a breeze to get on. Air Mesh insulated back panel insert keeps your back cool and comfortable while insulating the water in your reservoir Insulated tube cover keeps water in the tube cooler and more desirable to drink. Quickwick fabric keeps you dry and comfortable.