Sedeta&reg; 10000/3000 Grit Sharpening Stone Razor Sharpener Whetstone Polishing Tool Two Sides for Sharpening Knives Scissor Blade A fine-grained whetstone lubricated with oil, used for fine sharpening The Ruby sharpening stone and Agate Stone, For Polishing, Sharpening Can make mirror surface, mirror finish The Ruby Sharpening stone is made from sintered crystals of synthetic ruby It's extremely hard, maintain their shape well and are resistant to wear