They carry your drinks in style & keep them cold or hot for longer hours.With double walls made of stainless steel & cap with easy opening. BPA FREE. Made of 304 stainless steel (18/8 stainless steel). With FDA & SGS quality certificates. Free of aluminum and toxic substances (BPA free). They do not break. 100% recyclable. With double walls, to maintain the temperature for more hours. EXTERIOR HIGH QUALITY PLASTIC.