Used with a face plate, you can mount and turn work between centers. The workpiece is rotated by the lathe dog engaging with the face plate or a drive plate. The lathe dog mounts around the workpiece and engaged into a slot on the face plate or hole in the drive plate. Working between centers ensures that the workpiece is always perfectly centered on two points. The part can be removed and test fit, then replaced on the lathe and finished or modified. For quick jobs, you can turn a mounting point on a piece of metal mounted in the 3-jaw or 4-jaw chuck -- this becomes your headstock center. The lathe dog is then mounted on the work, a support for the tailstock is installed and the leg of the lathe dog is rested against the chuck to provide the turning force. A quick way to get the job done.