Work well, allow you to take a needle to better than factory. A bit faster and easier than my old time consuming method of dremmel and polishing wheel with silvo. Good tool to have to combat tip dry and put a finish on repaired needles. Would recommend any airbrush user keep a couple on hand and worth using even on new needles as more often than not, they are poorly finished or polished, and this can result in frustrating tip dry, especially on smaller nozzle sizes with Wicked opaques, or other waterborne acrylics. Polishing with these reduce my tip dry so that maybe once or twice in an hour I have to clean my tip instead of once every 30 seconds.
Be gentle, and always twist as you move across the pad stem to tip. Add a tiny bit of water if you want ultra smooth polish.
I put the airbrush needle in a drill and spun polished with 1500 Micro Fine "Wet" (with water on the sandpaper} to take out any abrasion marks. Then the same with the SharpenAir Polishing Pad. You need a magnify loupe at least 30x to see your results and to rework if needed. In the end the needle looks new. Awesome!