DOUBLE WALL INSULATION: Our classic water tumblers are double walled and vacuum insulated, which keeps your drinks hot up to 4 hours or cold up to 9 hours. The high-quality, no sweat design ensures your desk stays free of condensation STAINLESS STEEL SKINNY TUMBLER: Made of food grade stainless steel with Paint coating, no more worries about peeling or rusting.Highly durable construction and splash-proof design make the travel tumbler great for indoor and outdoor use, it's an ideal coffee tumbler for keeping. Dishwasher cleaning is not recommended PORTABLE&ECO-FRIENDLY: Thanks to its slim and sleek body, it is easy to carry and store , also it fits in most cup holders.