Adjusting your machine's position is now easier than ever. Simply attach the jog knob to the ACME lead screw on your machine and tighten using the M5 set screws included in the pack. you can attach a handle using the four M5 holes on the face of the knob. Also an interesting mention is that this knob doubles as mounting hub for projects that may require a wheel hub. Using the 4 M5 tapped holes, one can quickly attach this knob to a variety of applications.