Powered by AUTOSEAL Technology that provides on-the-go spill-proof & leak-proof confidence. Simply push the button to drink and release to automatically seal the lid. One-handed operation offers optimal on-the-go experience. THERMALOCK double-wall, vacuum- insulation keeps drinks hot up to 5 hours and up to 12 hours cold. Easy to clean lid. Underside of lid opens completely for easy access and thorough cleaning. One-piece lid, no loose parts to misplace.