The Lagerhead Black & Tan Turtle is a formed piece of stainless steel shaped like a snapping turtle which fits over the rim of a glass - you can pour your stout over the "shell' of the turtle, creating the perfect Black and Tan drink. The mouth doubles as a bottle opener. You can also use it to make other delicious layered beers. It measures about 5.5 x 3.25 x 1.75" tall. Markings resembling a turtle and its shell. Identified on bottom including patent # on bottom D470370. It is in very good, clean preowned condition. We are a smoke free home.