Product details:

(Who knew there was such a thing?!) For all those people, this is the tumbler for you. Our 20 oz 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.