Diablo, 4.5", 40 Grit, Steel Demon Corner Edge Flap Discs, Premium Zirconium Blend For Up To 10x Faster Material Removal When Compared To Standard Grinding Wheels, Design Offers Flexibility & Provides For Cushioned Grinding Effect, High Performance Flap Discs Combine 2 Steps In 1 By Simultaneously Grinding & Polishing.