Lapidary Glass Flat Lap Grinder Disc Magnetic Backing Plates 

Grinder Lap Magnetic Backing Plate,Magnetic Backing Plate,Magnetic Backer and diamond lap backing use these magnetic backing plates to turn you master lap into a magnetic master lap. Simply adhere to master lap with 3M adhesive paper. Please note these plates are not self-adhesive. These discs have a 1/2" arbor hole. When changing laps, simply slide the lap off in a sideways motion (rather than trying to lift or pick it straight up).  Choose from these sizes: Diameter: 6"  8"   12"  16" and 24"