Size Arbor Grit Maxrpm Type 4-1/2? 7/8? 36# 40# 60# 80# 120# 13300 T27 T29 5? 7/8? 36# 40# 60# 80# 120# 12000 T27 T29 7? 7/8? 36# 40# 60# 80# 120# 8600 T27 T29 Characteristics: * Provides the same hight performance as standard flap disc,but with 50% more usable abrasives. * The added abrasive gives a cushion to the product which provides a quick grind with less heat to produce a higher quality finish. * 30% longer life than regular density flap disc * Aggressive cut and long life,Less pressure for aggressive stock removal and long life.