These indicator knobs have any easy-to-grip lobed shape. It includes the knob only (dial indicators must be ordered separately). The knobs have a 60-degree angular range of mounting in either direction. Knobs have a reamed hole in the hub for direct mounting onto a machine spindle. Installs easily by tightening the setscrew. Center caps are available for applications without an indicator. The knob is silver gray color and made from AD12 aluminum alloy treated with a baked finish.