For grip wrenches using single-lead thread adjusting screw. Adapter threads onto a slide hammer with a 5/8"-18 thread. Grip wrench threads onto 7/16"-l4 end of adapter for pulling use This is usually included in most of the OTC puller kits. This tool has the ability to add more force when pulling. It threads onto slide hammer with 5/8"-l8 thread. It's very simple to use.