Universal Bite Valve Replacement - Directly replaces worn-out valves on most hydration bladders. Maintains leak-proof seal with precision inner post design. MedicalGrade Silicone - BPA free, 100% FDA-compliant material ensures safe drinking. 15 Second Installation - Slide on sheath requires zero tools/skills. Compatible with fixed/360°rotating/on-off valves. No tube modifications needed. 6 Pack Maintenance Kit - Includes 6 replacement sheaths. Enough for 3+ years' regular replacements (strong recomond 1 sheath lasts 6-8 months depond on use ). Adventure Proof Design - Withstands extreme temps (-40℉ to 400℉) and bite pressure. Verified fit for cycling/hiking/running hydration packs (1.5L-3L reservoirs). Silicone Imported SHEATH REPLACEMENT - Fits and replaces all HydraPak bite valves on our Reservoirs, SoftFlasks, and UltraFlasks. DURABLE SILICONE - Silicone sheaths are soft to bite and durable, include inner posts Sport type: Outdoor Lifestyle Item Package Weight: 5.7 grams