Digital Action Gauge
This is the first pocket digital device for measuring the action of the strings. Originally, this device was a tire/tread depth gauge for automotive. This idea for a precision setup device was brought to guitar community by inventor Davide Bissoli, in 2011. With a few changes it became a perfect setup machine. On the left, one of many models of digital tread depth gauge available in the market today. In the middle and on the right, a modified version which can be used as a digital string height gauge.