Contigo Autoseal Aria Vacuum Insulated Stainless Steel Travel Mug, 20oz, Charcoal Vacuum insulation keeps beverages hot for 7 hours or cold for 20 hours Patented autoseal technology for 100 percent leak-proof and 100 percent spill-proof performance Button toggles to lock, preventing accidental actuation when carrying inside bags or with other items Double-wall stainless steel construction eliminates external condensation 100-percent fda-approved, bpa-free materials; top-rack dishwasher safe