LifeSky Stainless Steel Vacuum Insulated Thermos Coffee Mug Travel Drink Bottle, 16 oz, Blue Durable stainless steel construction keep liquids HOT or COLD up to 12 hours Vacuum Insulation Technology where air is sucked out, creating a vacuum between the wall to minimized the effect of outside temperature Drink lid opens with push button ease and locks closed for carefree travel; Leak proof design to ensure no liquid can escape Lid is made out of BPA free plastic -- can be taking apart for easy cleaning