This extra long slotted wedge key key measures .325" wide by .114" thick by 1-3/4" long. As cast slot is 1/16" wide by 1-1/32". The head is slanted slightly, to fit the curvature of your big rifle's extra wide forend. Use it on 1-1/4" or wider barrels, or shorten this key as needed to fit a typical rifle.