Designed for square drives, you can use the PRO Impact Socket Set for hex screws, bolts, and nuts with your square drive wrench. The set is made from heat-treated chrome-molybdenum steel and is very resistant to high torque due to its thick walls. The black phosphate coating protects it from rust and corrosion. The socket inserts are laser-etched and color-coded for easy identification at a glance. They feature a groove and a pass-through hole. For extra strong hold, they can be secured to your impact wrench with a pin and ring.