#1 PREMIUM QUALITY - Made only from the High Quality Premium 304 18/8 Food Grade Stainless Steel. #1 SUPERIOR FINISHING INSIDE & OUT – Your tumbler will always feel smooth to the touch with a sweat-free design, An electro-polished interior will ensure your cups remain pure and rust-free, imparting NO unwanted flavors, giving you a clean tasting drink every time! Perfect design: We have improved the sealing ring. Good airtightness design keeps your drink hot and cold for a longer time. Safe Material: Made of top-notch food grade plastic, free of bisphenol A, environmentally friendly, durable, non-toxic, dishwasher friendly Leak proof: The leak proof cover adopts a unique double sealing technology design, so there is no need to worry about leakage, especially when filling up hot drinks or driving.