This extension unit is suitable for operating QLPDW pull down clamps from a distance. Attach an extension bar and hex socket (not included) to connect the extension unit to the clamp. The hex head can be turned manually or operated with an impact wrench. Body made from electroless nickle-plated1045 steel. Hexagonal shaft made from 304 stainless steel. The square shaft made from electroless nickle-plated SS400 steel.