Contigo Autoseal West Loop Stainless Steel Travel Mug with Open-Access Lid (Discontinued by Manufacturer) Vacuum-insulated technology keeps beverages hot for 4 hours, and cold for 12 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