This is a new old stock chrome finish, 12" size adjustable wrench replacement jaw for a S-K brand adjustable wrench. This one will fit the older brand 12" and perhaps newer ones too. The thickness of the jaw is .46" at the narrowest tip of the jaw, and the gear area diameter is .40". Please double check these size on your wrench before you order as it is possible this jaw design was changed slightly over the years. We will be listing replacement parts for several sizes of SK brand wrenches, as well as other brands. Ask us if you have any questions.