Discs with thin bristles for hard to reach areas do not require compounds. Abrasive grains throughout the discs clean metal surfaces, remove light fire scale and oxide, finish, blend, texture, pre-polish and polish precious and non-precious metal, acrylics, and ceramics. 3 discs per mandrel.Do not run handpiece in reverse! 20,000 rpm Max. Speed Diameters are 25, 20 & 15 mm (.984″, .787″, .59″). Each mandrel holds 3 discs. Color and grit listed below: 25 mm Dark green – 80 grit 20 mm Brown – 320 grit 20 & 15 mm Lt. green – 1000 grit 25 mm Dark blue – 120 grit 20 & 15 mm Blue Gray – 400 grit 20 & 15 mm Gray – 2500 grit 25 mm Dark Red – 220 grit 20 mm Lavender – 600 grit 20 & 15 mm White – 5000 grit SKU: FOR-AK11989 UPC: 098666082041 Brand: ORO MPN: AK11989 Micro-Tools makes every attempt to provide accurate information for each item. Actual packaging and/or specifications may be slightly different from the information and picture provided.B068L