VICMARC Manta Gauge
 
The Manta Gauge Master was designed by Vicmarc and dns Germany.  The advantages of the Manta are:
 
Reduction of the edge angles to easy-to-remember numbers.
Reduction to 5 edge angles of woodturning tools with a clear classification via symbols.
Two practical checking options for the edge angle: sighting and insertion.
The shape of the tip of the tool is just as important as the bevel angle.  The Manta shows the correct profile of the most popular widths of spindle gouges i.e. 6, 10, 13 and 20mm.
For skew chisels you are able to check the bevel angle as well as the skew angle: 55 degrees or 77 degrees depending on your preference.