There is probably an exact name for this but without it I will just do my best to "surround" it. Some kind of old wood handled protractor to measure and duplicate angles in woodworking mainly. It is an old tool with a locking mechanism that works. There is no marking on it I can find. The handle is about 4 1/2 inches long and the metal blade is about 6 inches, so fully extended it is about 9 1/2 inches long. It also resembles an old square so that may be part of the puzzle for naming it. First class shipping within US will be $3.50.