Designed for square drives, you can use the PRO Impact Socket Set for hex screws, bolts, and nuts with your square drive wrench. It is intended for fastening tasks in extensive assemblies or other demanding industrial applications. The PRO Impact Socket Set is made from heat-treated chrome-molybdenum steel and is highly resistant to high torque due to its thick walls. The black phosphate coating protects it from rust and corrosion. The sockets are laser-etched and color-coded, allowing you to find the right one at a glance. They feature a groove and a through hole. For extra strong hold, they can be secured to your impact wrench with a pin and ring.