Stainless Steel Outer And Inner. Double Wall Construction For Insulation Of Hot Or Cold Liquids. Snap-On, Spill-Resistant Lid With 9" Straw. Due To Vacuum Insulation Technology, Capacity Is 18 Oz. With Lid On. Keeps Drinks Hot Or Cold Up To 6 Hours. Non-Slip Bottom. Meets FDA Requirements. BPA Free. Hand Wash Recommended. Lids and Straws Packed Separately and Unassembled.