Ezprogear 40 oz Stainless Steel Coffee Mug Double Wall Beer Tumbler Vacuum Insulated Tea Cup with Handle and Lid. We crafted our tumbler with vacuum seal in between so that your drink temperature will not easily transfer through. The double wall is made for sweat free convenient so you will never feel a sweat when you fill with cold beverage or get hot to the touch when you fill hot beverage. This tumbler is made from high quality 304 18/8 stainless steel which makes it puncture and rust resistant. The tumbler comes with BPA free Slider Lid so that you can easily slide through for open and slide back for close.