Package contents: four silicone bite valve sheaths — keep a ready set of replacements to maintain reliable hydration performance and hygiene. Material and feel: softtouch silicone provides comfortable, loweffort sipping so you can drink easily during intense outdoor activity. Function: protective bite valve sheaths preserve the valve seal and drinking surface, helping maintain flow and reduce wear over time. Compatibility: designed to fit most hydration bladders and drinking tubes, including models with 360degree rotatable valves. Performance and durability: flexible silicone resists tearing and retains shape through repeated use and replacement cycles. When to : include these in routine maintenance to ensure consistent flow and hygienic drinking; replacing worn sheaths helps sustain hydration efficiency. Common uses Hiking and backpacking: swap in fresh sheaths before long trips to keep your bladder performing as intended. Cycling and trail running: comfortable, soft valves make quick sips easy without breaking your pace. Gym and daily carry: maintain hygiene and sipping performance for regular workouts or everyday use. Care note Rinse before first use and as needed; periodically as part of regular hydrationbladder maintenance to preserve comfort and performance.