You used to be able to buy this tool several years ago, it was called a "Yankee Punch"...but then it disappeared. We hunted around and found it again and re named it. It's called a "Screw Punch" because when you press down on the handle, the spring like mechanism in the shaft kind of screws the punch tube into the leather...or cloth...or whatever material you want to use it on, cleanly and smoothly. It easily works on leathers from 1 oz. up to about 8-9 oz....you can use it on 10 oz. leather but then you would have to exert some effort and you might have to push the punch a couple of times before the hole appears ...so if you need to punch holes in 9-10 oz. leather...save yourself some energy and use a regular drive punch This awesome tool punches perfect holes in garment leather as well as firmer leather, upholstery leather as well as tooling leather. (If you use this on garment leather, you will have to hold the leather down or else the leather will spin around like an idiot). If you are able and you want to give yourself a real treat, then this would be the way to do it. Some of you may have used or heard of the "Yankee" or "Screw Punch" before...if so, then you know how cool this tool is, and why it's a must for every toolbox!! Our Screw Punch comes with 2 replaceable punch tubes; sizes 2.0 & 2.5 mm, but we stock replacement tubes ranging from 1.0 mm up to 4.0 mm. Item #86-8561