Mastech Wire Tracker Test Cable Network Cable Telephone Cable Underground Pipe Ms6818 The transmitter measures 12 to 400V AC/DC voltage on a linear basis. the transmitter can display preset transmitting power,transmitted codes,its own battery energy The Transmitter can detect its own working status and display it on the LCD The sensitivity of the receiver can be adjusted either manually or automatically The receiver can sweep frequency automatically,both the transmitter and the receiver can work under mute mode