Tired of sending your valuable knives out for service? Try the WSTHOF Ceramic whetstone. With two sides, one can recondition a well used edge with the 400 grit side then fine tune with the 2000 grit side. – Coarse and Fine Grain (J 400 / 2000).- The optimum solution for sharp knives.- Suitable for use with water- Dimensions: L 15 cm/ 6-in x W 5 cm/ 2-in x H 2.5 cm/ 1-in