The Pearl GREENBACK™ Trimmable Zirconia Maxidisc features an extremely tough Zirconia abrasive grain. This Zirconia Grain is very tough and is excellent for heavy stock removal. The Pearl GREENBACK™ Trimmable Flap Disc has a longer life and self sharpening grains that remain sharp for the duration of its life. This premium flap discs features pearls Quickmount™ threaded hub for fast and easy disc changes. Call Panther Industrial today to try these top of the line Pearl GREENBACK™ Maxidiscs!