"Our development team took up the challenge of creating the first (and only) 100% plastic-free sport bottles in the world. By combining two safe and proven materials, Food Grade Stainless Steel and Medical Grade Silicone, we created the Pura SportTM collection of water bottles. Each bottle features our patented, medical grade silicone Big MouthTM sport top. The Big Mouth allows a free flow of liquids when open and is leak proof when closed. Available in 18oz, 28oz and 22oz Insulated sizes. With Pura you can rest assured that you are always using the safest and most eco-progressive bottle on the market. One Life... One Bottle General Instructions: Wash before first use. Boil for 5 minutes to sterilize. Remove the sleeve from the bottle at least one time per week to clean between the bottle and sleeve, more often in humid climates. Dishwasher safe. How to install sleeve: Add baking soda to the inside of a dry sleeve then slide onto the bottle. Rinse thoroughly. OR At the sink, spread a pea-sized drop of liquid dish soap inside the sleeve then slide the sleeve onto the bottle. Rinse thoroughly."