LifeSky Stainless Steel Vacuum Insulated Thermos Cup Travel Mug, 18 oz, Green Modern Stainless Steel construction with smooth glossy finish Vacuum Insulation Technology where air is sucked out, creating a vacuum between the wall to minimized the effect of outside temperature Keep liquids HOT or COLD up to 12 hours. Leak proof design lid with easy twist and pour operation for quick liquids access Built in cup with convenient handle Lid and cup is made out of BPA free plastic -- can be taking apart for easy cleaning