This 20 oz Hazel Oak Farms branded tumbler has all the same design and sophistication as its big brother, but in a grip-friendly size. Dual walls are cold formed out of 18/8 stainless steel (a.k.a. 304 stainless steel) and vacuum insulated for outstanding temperature retention. A copper lining on the inner wall helps evenly distribute heat or cold throughout your favorite drink. Customized and manufactured by Big Frig, LLC.