Flap disc, high density Jumbo blue zirconia, 40 Grit Type 29, depressed center 4-1/2 inch with 5/8 inch-11 arbor ZA40, for right angle grinders. Cuts fast and outlast sanding discs 10-to-1. Great flexibility. Ideal for rough or fine finishing. High density discs are ideal for the extra tough jobs. Long lasting, cooler running Jumbo style. Cuts fast and outlasts sanding discsIdeal for rough or fine finishingGreat flexibilityMaximum RPM of 13300