US CamelBak CBRN Hydration Training Kit, 4-piece, Surplus, unissued - Varusteleka.com
Amazon.com : Aquatic Way Bite Valve Replacement Mouthpieces fits Camelbak and Most Brands (4-Pack), with Shutoff Valve and Tube O-Ring for Hydration Bladder and Backpack Water Reservoir : Sports & Outdoors