These heavy duty work supports are ideal for preventing the workpiece from chattering and deflecting. The support plunger can be raised or lowered by turning the cap screw. The positive locking mechanism allows the ball-thumb-screw style to offer high support capacities. Mounts with socket head cap screw. Compatible with the BJ650 remote control unit is available for remote operation at a distance (sold separately). Made from SAE-1045 steel with a black oxide finish.