Thermos 18 Ounce Hydration Bottle, Stainless Steel THERMOS vacuum insulation technology locks in temperature to preserve flavor and freshness to keep beverages cold for up to 12 hours Durable 18/8 stainless steel interior and exterior withstand the demands of everyday use Drink lid opens with push button ease and locks closed for carefree travel Sweat proof design won't leave water rings 18 ounce capacity