We design high quality impact hex drivers for pneumatic screw drivers. It is a tool designed for operation with a pneumatic nut runner. It has a male hex drive on one end that fits into the female hex shank of the nut runner and on the other end is a single hex socket. The range covers 1/4" (6.35 mm) hex drives for nut sizes in range of 4 mm to 20 mm in three lengths - 75 mm, 100 mm and 150 mm. We can also provide other sizes including SAE on request.