As said by the 11th Doctor. What better description of The Doctor than a mad man in a box?
Keychain is double-sided with the same artwork on both sides. It's made of FRP Plastic, which is strong and won't break. The artwork is dye sublimated, which is a process where the ink becomes part of the plastic. This process makes it so that the artwork doesn't scratch off, peel, or fade.
Keychain is 2.25" long and 1/16" deep (5.71 x 5.71 x .16 cm). Artwork has a whitebackground, with blue lettering and artwork. Metal ring is silver-tone, attached with a snap-plastic closure. Key pictured for size comparison, and not included with purchase.