The double-wall stainless steel construction along with the copper inner wall, keep your drinks warm or cold for 12h and cold for 48h.  .: Screw-on lid with a built-in bluetooth speaker .: Bluetooth range of 10 meters (33 feet) .: Double-wall stainless steel construction .: IPX6 Water Resistant .: 22oz (0.65 l) .: BPA free