DMT 10-Inch Dia-Flat Lapping Plate, 120 Micron/120 Mesh (120 grit)

Yes, this is sort of like an extra-large and extra-heavy-duty version of the well-known D8XX Extra-Extra-Coarse stone. It's a monster!

DMT recommends the 95 micron (160 mesh) version for flattening 1000 and finer grit stones, or this 120 micron (120 mesh) for 1000 grit and coarser stones. Yes, you can still use this on finer stones but it will leave them more scratched than a finer lapping plate will... this isn't always a problem, but if you want a highly polished edge (or you're sharpening a straight razor for example), it's probably not ideal. 

--- DMT says:
Dia-Flat™ Lapping Plate is designed to easily flatten all conventional stones and waterstones in less time than other methods. Using the new revolutionary DMT® Diamond Hardcoat Technology™ this lapping plate outlasts any other diamond coating in the market. With a consistent, aggressive diamond surface and precision ground, hand certified flat to +/- 0.0005”, the Dia-Flat assures rigid execution when flattening stones. Greater surface area for ease of use. Durable construction will provide years of consistent performance and reliable service. For proper tool maintenance, woodworkers, chefs and other professionals rely on the superior quality and versatility of DMT® products. Made in USA.

• 120 micron / 120 mesh
• Precision ground flat to +/- 0.0005”
• Aggressive surface to facilitate quick and easy flattening of conventional and Arkansas stones and waterstones
• DMT® Diamond Hardcoat Technology™ outlasts any other diamond coating in the market on lapping plate
• Largest surface area of any diamond lapping plate - 40 square inches (10" x 4") or 50% larger than other diamond lapping plates
• Durable construction will provide years of consistent performance and reliable service

 DMT offers the Dia-Flat in two versions, a 120 micron / 120 mesh and a 95 micron / 160 mesh. Each lapping plate is made with the same Diamond Hardcoat Technology™ and precision ground, hand certified flat to +/- 0.0005". The 95 micron / 160 mesh is less coarse than the original 120 micron version.

NOTE: The surface of these stones may appear scratched and there may be small indents/pits in the surface, but it's just a by-product of their manufacturing and does not affect performance.