Tormek Angle Master WM-200
Sets and measures the edge angle. Adjustable to any stone diameter from Ø 250 mm or 10" down to Ø 150 mm or 6". Measures from 10° to 75°. Magnets keeps it in place. You can use it to set the jig to the grindstone so that it grinds your tool to any desired edge angle from 10° to 75° and you can use it to measure an existing edge angle on a tool.
It is designed to work on any grindstone diameter from 250 mm (10") down to 150 mm (6"). You achieve an exact setting irrespective of the degree of stone wear.