Manufactured with m2 high speed steel extra-hardened for maixmum durability and long life with impact drivers tip of drill end is designed to start fast with minimal walking, and tip of extractor end is serrated for increased torque to remove even the toughest bolts and screws doublelok technology ensures both ends of bit lock securely in impact drivers and quick change chucks, enabling use of a single bit to remove stripped, damaged, or rusted screws and small bolts in 3 easy steps: drill,flip bit, and extract.