I have one, but have never used it! I turned a handle down on my wood lathe and then I drilled 1/2" hole down in the front end, and cut 1/2" circle of Buffalo leather that a good friend sent sent me, I used contact cement around and on top of every layer except the top one. I think I used 6 layers, and use it to back up with, once you got your neddle threw where you want, you can move it to the side or below and still have a backer!
Just my 2 cents worth!
ACE