|A 3/4" open end wrench can be used to turn the socket while impacting the fastener. A locking pin in the driver keeps the bit holder in place on the square drive for safe operation. The bit holder can be removed from the driver by depressing the pin. Works faster than hand impact tools. Especially useful for removing brake rotor screws. The tool works with 5/16" hex impact bits. Kit includes Phillips #1, #2, #3, #4 and a straight slot bit.