[Product name]: professional sharpening stone [Function]:Sharpen blunt knife [Scope of application]: home kitchen, restaurant kitchen, outdoor, etc. [Knife types]: kitchen knives, fruit knives, boning knives, scissors, etc. 7 different pieces of stone grain 120 240 600 800 1000 2000 3000 GRAIN. The diamond stone is smooth, it uses a single crystal diamond, resistant to wear, long lasting. size:16x2.4 Cm Material:Diamond Colour:black+silver Material:diamond Package Contents: 7 x Diamond Sharpener Whetstone Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.