ITEM NAME:2pcs/set Water Bladder/ Hydration Pack Drink Tube Bite Valve Dust Cover Cap Description: PP materials dust cover To keep bite valve clean and dirt free Overall Height: 50mm/2". Cap Outer Diameter: 26mm/1" Mount on hose part inner diameter: 19mm/0.75", 13mm/0.5" Outdoor camping hiking hydration packs replacement parts Package Includes: 2 Piece Hydration Pack Bite Valve Cover (Blue + Black).To keep bite valve clean and dirt free. Overall Height: 50mm/2". PP materials dust cover.