This P150 grit quick-change sanding disc is two inches in diameter sanding and has an aluminum oxide abrasive. This roll-on disc is perfect for use in welding, metalworking, and in maintenance, repairs, and operations. It can be run wet or dry and is resin-bonded for heat resistance. This sanding disc has YF-weight polyester backing that is water-resistant and can withstand grinding speeds up to 25,000 RPM.