Our insulated tumblers are made of 18/8 Food Grade Rust-proof stainless steel instead of cheaper 201 steel finish. Each tumbler with a superior non fading coated finish for maximum durability! Non fading & long-Lasting Powder coating keep its stay colorful finish and look more elegant and noble Smooth surface will ensure your cups remain pure, Sweat Free giving you a clean tasting drink every time! Electro-polished interior imparting no any smell, giving you a clean and hygienic drinking experie