Silicone boot fits 40oz stainless steel Owala FreeSip water bottles; Not intended for use with tritan plastic water bottles; Not intended for use with tritan plastic, Kids bottles, Freesip Twist, FreeSip Sway, 40oz Tumblers, SmoothSip coffee tumblers. The silicone boot is like a phone case for your water bottle - it protects it from scratches, dents, or zombie attacks. It absorbs any damage that comes its way. Offered in 5 bright colors to mix and match with your favorite Owala bottles. Owala water bottle not included. Dishwasher safe.