Double-wall, vacuum-insulated design with a copper lining enhances temperature retention Stemless, durable, reusable wine glass alternative with advanced temperature retention Flip ‘n’ Sip lid features a mouth opening cover that opens easily & clips securely into place when open or closed Sweatproof exterior (no condensation!) so tumbler isn’t slippery & hands stay dry. Built-in rubber coaster on the bottom. Made with food-grade 304 stainless steel. Durable, clear gloss-coated finish exterior, Dishwasher safe