The SENSO™ Comfort Touch Bottle has a unique thermo-core interior in a 12 oz bottle. Simply shake the bottle to experience a warming or cooling sensation on the outer bottle surface that keeps hands warm & comfy with hot beverages, or a pleasing cool touch with cold beverages. This bottle also features 18/8 stainless steel construction with powder-coated matte finish and a wide-mouth screw-on rubber-seal cap with silicon carrying ring. BPA Free & FDA certified.