The 9PCS knife sharpening stone kit by SATC includes dual whetstones with grits ranging from 400 to 8000, making it versatile for rough, normal, fine sharpening, and polishing. The kit features a white flattening stone made of aluminum oxide, black flattening stones made of silicon carbide, and red/beige stones made of white fused alumina. The whetstones come in a compact 7.1x2.4x1.18 inch size and are designed for wear-resistance, ensuring quick and easy sharpening with a non-slip surface. Ideal for home kitchen use, this sharpening stone kit is a valuable addition to any chef's arsenal.