Designed to GRIP up to 100% rounded fasteners. Replaces standard broken studs, lug nuts, grease nipples, and much more. Laser markings for greater visibility. Bi-Directional Design enables loosening and tightening of new and damaged fasteners. Designed to be hammered onto object that is being extracted (do not hammer on pusher rod). Designed for hand and impact use no impact on pusher rod! Sizes included – 19, 20, 21, 22, 23, 24, 25 MM.