YSTD&reg; Knife Razor Sharpener Stone Whetstone Polishin Oilstone Grit 3000 & 10000# The Ruby sharpening stone and Agate Stone,For Polishing,Sharpening Its extremely hard,maintain their shape well and are resistant to wear Material: Ruby stone and natural agate(as it is natural stone, some stone has other color like black or white dot etc, please pay attention) Model: 3000 & 10000 Grit Dimension: 50mm x 25mm x 10mm/1.97" x 0.98" x 0.39"