17oz One Mug 3.0 tumbler style with rubber grip ring. Onyx Metallic With vacuum furnace insulation, the outer stainless steel surface remains cool while beverages stay hot for 3 hours and cold for 6 hours. The sipping lid has a slide-tab closure that prevents splashing Attachable"docking station" base twists off to fit into a vechicle cup holder;when attached it adds stability for use on a work surface