Ronald van de Ing has designed this gauge to precisely measure the radius or bend of your blades. The gauge clamps itself onto the steel with integrated magnets which makes measuring more easy and precise.
Measurements with this gauge are more precise on a blade that is bended and as well rockered. The 3-point positioning of the frame aligns the gauge more accurate.
The gauge comes with a chart that indicates a value for each possible radius.
Read here how to read your gauge.