Atoma Lapping Plate w/ handle (140 grit):
This is the best flattening and Whetstone maintenance product out.
Unlike other flattening stones this one will not become even over time.
Used by many professional sharpeners in Japan.
*This is a very course. Can be used in a major repair of a knife.
Regular use in a sharpening progression is not recommended
If your serious about sharpening you will enjoy this!