Include insert bits for spark plugs, screwdriver bits with square drive for slotted, Phillips, TX (with front hole) and internal hex inserts, as well as angled internal hex keys. The ratchet mechanism is the central element, made from a single piece of CrV steel. It is hardened with a perfect tooth profile; several of the 52 teeth engage simultaneously to transmit extremely high torque. The quick-release mechanism allows for the removal of the inserts at the push of a button. The set comes in a robust, welded steel box, powder-coated for durability, with distortion-free, unbreakable inserts made from injection-molded polypropylene. The product is oil and acid resistant and easy to clean, with clear and durable markings for all insert sizes.