Just noticed these on Supergrit the other day, and bought a couple. Have to post them because I like the color. According to Supergrit, "If you like Norton 'Blaze' or 3M Cubitron II, you will love these purple 90% plus ceramic belts made by Deer Abrasives. These premium ceramic belts will grind the hardest steel. They require significant pressure to create fracturing of the grit and outlast most other ceramic belts. Bora7 performs best on high speed sanders like 2" X 72". It is not recommended on slower 132" long sanders." I have not used them yet, but we'll see.