Servicing MacPherson struts is more convenient and affordable when this tool is in your shop. It fits a wide range of struts and no special adapter shoes are needed. The compressor jaws are held in place by safety lockng pins. Tool compresses springs of 4in. to 9in. O.D. with wire diameters of 7/16in. to 11/16in. It can be driven by an impact wrench. Made in U.S.A. Lifetime Marathon Warranty.