A flat hip flask, perfect for carrying paint remover or anti-freeze or whatever it is you people drink.

Size about 9.5 x 13 x 2 cm / (3.5" x 5" x 0.8").

A hip flask, if anything, is an item you'll want engraved. Unlike a tattoo, it's not permanently on you if you regret it later. Made from stainless steel apart from the hinge, which is nowadays. plastic. Stainless steel doesn't collect weird odors, but you shouldn't store booze in it for too long anyway. It isn't an oak cask that improves your hooch.