The Faulk String Level Gauge is basically a holding block that suspends a 1/2″ rule over a two or three string unison. A technician plucks the strings with the dampers raised. When all the strings vibrate against the edge of the rule, the strings are level. Something new! This new gauge now comes with a sturdy aluminum holding block that will resist tipping over as you work. More improvements from Faulk Piano.