Awesome 3d printed comma wheel he calls it. The hub attaches to the parallax knob and you attach the parallax wheel to the hub via magnets. The system doesn’t look like it mars anything from my previous one. They’re $100 from dealer I’m willing to sell for $60 shipped PayPal, Zelle, whatever works. Again it’s brand new never installed. Comes with what you see. With these you use masking tape to mark distances
