Check the listing for details. Sharpal Diamond Lapping Plate 10 x 4 Inch 220 Grit. Condition: New. Listed at 86.95 USD. The Sharpal Diamond Lapping Plate features a 10" x 4" monocrystalline diamond surface with 220 grit (60 micron) for precision sharpening and lapping. Ideal for maintaining a razor-sharp edge on a variety of blades.