A fast cutting medium grit Crystolon on one side and a fine India abrasive surface on the other for producing keen, long lasting edges on quality tools. Crystolon side is dark grey in color, India side is orange. FeaturesSmooth cutting aluminum oxide abrasive (India Side)Ideal for deburring, generating keen edges and finishes (India Side)Premium silicon carbide abrasive (Crystolon Side)Ideal for general sharpening (Crystolon Side)