Contigo AUTOSEAL West Loop Vacuum-Insulated Stainless Steel Travel Mug with Easy-Clean Lid, 24 oz, Stainless Steel Vacuum-insulated technology keeps beverages hot for 6 hours, and cold for 18 hours Backed by the Contigo Lifetime Guarantee against any manufacturing defects in materials and workmanship AUTOSEAL is America's #1 selling line of Travel Mugs Patented AUTOSEAL lid automatically seals between sips to ensure no spills Hand washing recommended; lid is dishwasher safe