Our Dia-Flat Lapping Plate is designed to easily flatten all conventional and water stones in less time than other methods. Using the new revolutionary DMT Diamond Hardcoat Technology - this lapping plate outlasts any other diamond coating on 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. With 40 square inch surface area for ease of use and durable construction, it will provide years of consistent performance and reliable service. Comes with hand-certified-flat certificate and instructions for use. Size is 4˝ x 10˝. Made in USA.