18/8 Recycled stainless steel; naturally BPA-free, Double-wall vacuum insulation, FlowState™ 3-position lid. Easy-carry handle, comfort-grip and narrow base that will fit most cup holders. Will keep your water cold for 9 hours and iced for 40 also 5 hours hot! Lid features a rotating cover with three positions: straw opening designed to resist splashes with a seal that holds the reusable straw in place, a drink opening and full-cover top. Hand Wash Only