A fine-grained whetstone lubricated with oil, used for fine sharpening.The Ruby sharpening stone and Stone,For Polishing,Sharpening.Can Make Mirror surface, mirror finish.The Ruby Sharpening stone is made from sintered crystals of synthetic ruby.Its extremely hard, maintain their shape and are resistant to wear.Size:50*25*10mm(1.97*0.98*0.39 inch)Model:3000 & 10,000 GritMaterial:Ruby stone and natural Color: red & white(as the )Mainly used in industrial instrumentation, precision parts, miniature knives, , measuring tools, cutting tools, instruments, carbide, etc.Package included:1x Two Sides Jade SharpenerNote:Light and different displays may cause the color of the item in the a little different from the real thing.The measurement allowed error is +/-1-3 cm.