These diamond knife sharpening stones are made of quality emery abrasive, wear , not easy to rust, sturdy and , not easy to deform, and the diamond whetstone has a faster speed than the traditional whetstone. There are four different diamond sharpening plates in total for knife sharpener. They respectively are #240 #400 #600 #1000, so you can choose to use them to sharpen in accordance with their different speed and smoothness. One of the most outstanding features of this diamond sharpening plate is that there is no need to use water when you are sharpening . Compared with the sharpening stone, this sharpening plate is proved to be working more efficiently. These angle diamond sharpening stones are designed with a simple and generous shape, and the edges are smooth and neat, without scratching, non-slip and astringent, designed to improve overall durability and sharpening effect, improving work efficiency. There is that this diamond sharpening plate has a wide range of application and it can be widely used in all kinds of cutting tools, such as tools grinding, scissors, chisels, plane irons and kitchen knives and more. Colour:As Shown Material:diamond Package Contents: 4 * 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.