MASTECH MS8229 Auto Range Multimeter & Temperature Humidity Light Lux Sound Level Meter Tester 5 in 1 with Back Light Portable Professional Measuring instruments with large LCD digital display and Back light Overload protection and low battery indication light and sound alarm to prevent misconnection of test leads 5 in 1 digital multi-tester AC/DC voltage and current, resistance,frequency, duty, capacitance, as well as continuity and diode test