General Tools 8492 Square Drive Bits The General Tools and Instruments 8492 Square Drive Bits, Set of 2 are a specialty bit driver head for specialty screws used for woodworking These bits are meant for square head screws #2 The small bit is 3 inches and the larger is 6 inches, different depths for different applications. Because of the shape and fit of the driver and screw, its easier to start a screw one handed The bits can be used with both an impact driver, or also with a regular drill The General Tools and Instruments 8492 Square Drive Bits, Set of 2 are a specialty bit driver head for specialty screws used for woodworking These bits are meant for square head screws #2 The small bit is 3 Inch and the larger is 6 Inch, different depths for different applications Because of the shape and fit of the driver and screw, its easier to start a screw one handed The bits can be used with both an impact driver, or also with a regular drill