Premium Materials: Crafted from premium silicone, these water bottle stopper replacements are , , and safe for both hand washing and dishwasher use, which can maintain even after repeated removal and cleaning. Effortless Installation & Maintenance: Simply insert the replacement bottle stopper into the mouth of the water bottle and fix it in the appropriate position. The replaced water bottle mouth stopper can be easily disassembled and cleaned, providing you a lot of convenience. Leak-proof Performance: These water bottle mouth stoppers deliver exceptional leakproof performance. The custom-designed components maintain the your bottle's functionality while providing enhanced sealing protection. It is recommended to replace the stopper every two to three months for a better experience. Color: A:Black Material: Silicone Package Contents: 4 x Water Bottle Replacement Stopper Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.