Zojirushi’s proprietary double-wall stainless steel vacuum insulation keeps beverages hot or cold for hours. Leak-proof*** lid. Splatter-proof design lid prevents excess condensation on the stopper from being flung off while the lid opens. A special manufacturing technique was used to make the body ultra-lightweight and compact. Sports drink OK. Ergonomically designed for one-hand operation. BPA-Free (All areas that come in to contact with food and beverage).