Our insulated stainless steel coffee Mug Tumblers feature double-wall, vacuum insulation with a clear, slider lid. They are 2X heat and cold resistant compared to other tumblers and are made from 18/8 gauge stainless steel. The stainless steel is powder coated with the color of your choice of laser engraved design. SPECIFICATIONS Double Wall Vacuum Insulation Sweat Free Technology Superior Hot/Cold Retention Permanently Etched, Laser Engraved Holds 15 oz of liquid