Sharpening Japanese knives with a whetstone just got a whole lot easier. Simply slide a guide rail onto knife blade to create the ideal 10° to 15° angle. This two-piece set works perfectly for a variety of blade sizes and shapes. Small guide rail is suitable for knives with blade lengths less than 6", and the large guide rail is for blades longer than 6". Guide rails are lined with plastic to minimize scratching on the knives during sharpening. Hand wash and dry. 2" wide. Made in Japan.