【Wide Compatibility】HEYSKAY protective silicone boot is compatible with New Owala FreeSip Sway 30oz & 40oz and FreeSip Tumbler 40oz,also perfect for Stanley Quencher 30&40oz and Stanley lceFlow Tumblers 20&30 oz. It also fits other brand water bottle which bottom diameter is from 2.85inch to 2.95inch. NOT intended for Owala tritan plastic water bottles. 【Food Grade Material】HEYSKAY bottom boot is made of food grade silicone material, BPA-Free, odor-free, safe for your daily use. And it is thick enough to protect your Owala water bottles from damage, dings, and scratch and prevent annoying noise when landing your flask. 【Easy to Install and Remove】Designed with a small hole on the bottom for air outlet, supper easy to install your flask boot. Our silicone boot can withstand stretching and folding, washable and reusable. 【New Looking Creation】We have different colors and print designs for selection, try mutiple colors/designs, mix and match to create a new looking for your water bottle. 【Satisfactory Customer Service】We stand by our products! If you have any questions or concerns, quick customer service & pleasant purchase from Heyskay can be assured. HEYSKAY protective silicone boot is perfectly compatible with New Owala FreeSip Sway 30oz & 40oz and Tumbler 40oz,also perfect for Stanley Quencher 30&40oz and Stanley lceFlow Tumblers 20&30 oz. It also fits other brand water bottle which bottom diameter is from 2.85inch to 3.65inch. NOT intended for Owala tritan plastic water bottles