Our electrical fault indicator is a device that simultaneously monitors the hot, neutral and ground wires during your Nuheat installation. The MatSense Pro will set off an AUDIBLE alarm when the sensor finds an open circuit or the sensor detects short circuits in the mat. The MatSense Pro is the installers safeguard to ensure homeowners that their Nuheat mat(s) are installed correctly every time. Simply connect the conductor wires and ground to the MatSense Pro and turn it on. Using the MatSense Pro does not replace the need to test the continuity of the Nuheat mat(s) prior, during and after the installation with a digital Multi Meter.