Made of 40Cr alloy steel with high overall hardness and excellent toughness. It is not easy to deformation or break during long-term auto repair work, but also has a long lifespan Specially designed for short shaft threads, transmission shaft screws, uniform speed universal joints, half shafts and other parts to quickly repair loose teeth, rusted and damaged threads for accurate repairing effect Equipped with a dedicated box, so you can keep your tools organized and prevent them from getting lost. It is easy to carry when you go to repairs, and also helps to organize and store Hexagonal design, can be used with wrench or socket, evenly distributed during the repair process, non-slip and stable and easy to operate Designed to quickly and precisely handle damaged or rusted threads in a variety of repair scenarios, Manufacturer: Netbiio