Stainless Steel Outer And Inner. Double Wall Construction For Insulation Of Hot Or Cold Liquids. Vacuum Insulated. Unique Spill-Resistant, Push-Button Sip Through Lid. Push Lid Top To Drink, Push Again To Close. Multi-Flow Lid Helps Control Intake of Hot Or Cold Liquid. Non-Slip Bottom. Meets FDA Requirements. BPA Free. Hand Wash Recommended.