Wicked Edge Premium Grit Diamond Stones Pack. These Diamond Stones have a break-in period of about 20 sharpening sessions and an average lifespan of 700 sharpenings. Specifications for Wicked Edge Premium 400/600 Grit Diamond Stones Pack: Manufacturer: Wicked Edge Grit: 400 600 Medium Fine Fabric/Material: Diamond Color: Green/Yellow/Grey Size: Pair Length: 6 in Width: 2.36 in Height: 1.57 in Overall Length: 6 in Features of Wicked Edge Premium 400/600 Grit Diamond Stones Pack: Grit Range: 400 (medium-coarse) and 600 (coarse). Use Case: Scratch refinement and creating a dependable working edge. Break-In Period: Approx. 20 sharpening sessions. Lifespan: Up to 700 sharpenings per stone. Package Contents: Premium Monocrystalline 400 Grit and 600 Grit Diamond Stones Wicked Edge WE400600: Medium Fine 400 Grit / Fine 600 Grit Diamond Sharpening Stone