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. Knob is silver grey color and made from AD12 aluminum alloy treated with a baked finish.