HEYSKAY protective silicone boot was designed for 24oz 32oz 40oz stainless steel Owala Twist,FreeSip or Flip water bottles; Also perfect for Owala 40oz tumblers and Stanley Quencher(30/40oz) H2.0 and Stanley lceFlow (20/30 oz) Tumblers. It also fits other brand water bottle which bottom diameter is from 2.85inch to 3.65inch. NOT intended for Owala ..