Gregory Bite Valve Cover Optic Blue One Size. Compatible with all of Gregorys 3D Hydro Reservoirs. Specifications for Gregory Bite Valve Cover: Manufacturer: Gregory Size: One Size Weight: 0.14 oz Pack Application: Day Hiking Color: Optic Blue Hydration Compatible: Yes Fabric/Material: HDPE/EVA Height: 1.1 in Features of Gregory Bite Valve Cover Bite valve cover with integrated tether Compatible with Gregory's DryLock Magnetic Bite Valve Thread tether over hose before bite valve to secure cover Fits up to a 0.5" / 13mm outer diameter hose Package Contents: Gregory Bite Valve Cover Gregory 136978-5583: Bite Valve Cover Optic Blue One Size