Never spill another drop. 100-Percent spill- and leak-proof travel mug uses exclusive AUTOSEAL technology to prevent accidental spills. Press the AUTOSEAL button to sip, and release the button to automatically seal. This self-sealing lid technology is combined with a double-wall, vacuum-insulated, stainless steel mug, providing exceptional temperature retention. Beverages stay hot for 6 hours or cold for 18-hour.