18-8 stainless steel dual wall, copper lined vacuum insulation. Deep draw liner for a more permanent vacuum insulation. Vacuum insulation provides optimum heat retention at least 8X longer. Hold your beverage at the ideal drinking temperature at least 8X longer. Featuring our patented designed lid that features lip and finger grooves that allow you to position the drinking spout without even looking. Includes a leak proof screw on lid with a visual open/close push button locking closure and can come apart for easy cleaning. And features a silicon non-slip band. Made of FDA compliant materials.