This tool is used to hold your work on an MFT or similar table with 20mm holes. You can print 1 or 2 dogs and use 1x M6 20mm hex head bolt to attach it to the knob. The dog is threaded already so no need for a nut. The stop can be used to plane against or you can push the stop against a your work piece to hold it against another dog or fence. Happy Printing!