This traditional tail vise also uses one large screw, either wooden or metal. It consists of a movable block with one or more dog holes in it, the movable block rides in a large mortise in the workbench. The jaw has a face that contacts the bench top, and the dog holes are in line with the dog holes on the bench top. The two main varieties of this vise depend on whether the screw nut is mounted in the bench or on the dog hole block. When the screw nut is mounted on the dog hole block the installation is more complicated and expensive, but the screw does not move in and out as the vise is used.