With the Bosch 2609255704 Heavy Duty keyless chuck, you change drill bits quickly by hand without needing a chuck key. Whether you are replacing a worn chuck or upgrading from a keyed version, this robust keyless chuck provides a clamping range of 1.5 mm to 13 mm for cylindrical bits. The 1/2"-20 unf female thread connection mounts directly and securely onto compatible rotary drills, impact drills, bench-mounted drills, and cordless drills. Supporting both forward and reverse rotation, its integrated locking mechanism ensures a firm and reliable grip during demanding drilling tasks.