Diablo, 4.5'', 40 Grit, Steel Demon, Speed, Hub Flap Discs, Premium Zirconium Grain Blend For Up To 10x Faster Material Removal When Compared To Standard Grinding Wheels, Special Flap Design Offers Flexibility & Provides For Cushioned Grinding Effect, High Performance Flap Discs Combine 2 Steps In1 By Simultaneously Grinding & Polishing.