The Klean Kanteen insulated mug is made from food grade stainless steel & has a durable double walled construction with high performance vacuum insulation. It will keep the contents hot or cold & combined with the Pint Lid Cap this high quality, and quite frankly beautiful mug, transforms into the perfect commuter cup for your early morning brew. 18/8, food-grade stainless steel Durable & wont break like glass Electropolished interior Laser-etched exterior Doesnt retain or impart flavors Lifetime warranty