This is a replacement board for the eddy sensor board used in Road Show and Scared Stiff. The board has been redesigned with large ground planes to reduce electrical noise and plays just like the original.
It has a very intense indicator LED that you can observe indirectly.
The auto set system precisely calibrates the board at every power up, and allows for maximum sensitivity. Unlike a pot-based system, it can accomodate changes in system characteristics over time without intervention