The W7 Mini Diamond Whetstone can be used to sharpen, hone or file any hard material. Unbreakable, unbendable, and convenient to carry. Handy Mini Whetstone 70 x 25 x 5mm thick. No messy oils needed, sharpen dry or with water. Durable construction will provide years of consistent performance and reliable serviceSelect Option Black 220 Grit - Extra CoarseBlue 325 Grit - CoarseGreen 1200 Grit - Extra FineRed 600 Grit - FineSet of Three Add to Basket Quantity