Compatible Models The aluminum disc master base plate is designed for Flat Abrasive Wheels, Backer Disc, Slant Cabber Polishing Machine, and is compatible with Diamond Flap Lap Wheel. Function Aluminum Disc Master Lap Base Plate serves as the tray chassis/base for grinding disc sandpaper and polishing leather on angle machines, and as the jade polishing tray for jade polishing discs. Comfortable to Hold Aluminum main base plate measures 8 inch diameter with a 1/2 inch hole, suitable for 1/2 inch mandrels. Well made, standard size, plated finish, with edges softened to reduce the risk of injury. Note This aluminum support disc has no diamond coating and cannot be directly used to grind stones, knives, jewels, wood, or other hard materials. It is an attachment to the grinder and cannot function as a standalone grinding tool. It acts as a support plate in the grinder and provides a top surface for grinding paper, discs, or pads.