Check the listing for details. Shapton Lapping Disc – 2-3/4” Diameter. Condition: New. Listed at 19.99 USD. Shapton Lapping Disc – 2-3/4” Diameter, 180861, Cleans impacted Waterstones, Used wet with light pressure, Each disc has two surfaces – a grooved side for slightly finer results and a flat side, 2-3/4" in diameter, 24 mm (just shy of 1") thick, Rinse the sharpening stone completely after using the lapping disc to remove any stray grit. Does not substitute for occasional stone flattening., Shorten your sharpening time by maintaining your waterstones’ efficiency with the Shapton Lapping Disc. When your stone becomes clogged and dirty with sharpening debris, it loses its effectiveness, but you can restore its original capability with this disc. Each disc has two surfaces – a grooved side for slightly finer results and a flat side. Both surfaces can be used. Rinse the sharpening.