Klein Tools MM450 Multimeter is a TRMS auto-ranging slim multimeter that measures AC/DC voltage, AC/DC current, and resistance. It can also measure temperature, capacitance, frequency, duty-cycle, and test diodes and continuity. It features a high visibility, reverse contrast display with an optical sensor to automatically optimize viewing in dark or bright ambient light. The slim profile of the MM450 makes this meter almost the size of a cell phone and it conveniently fits into most pockets. The MM450 features the same quality leads you have come to expect from the Digital Multimeter line at Klein Tools. Years of field research, combined with extensive input from electricians across America, inspired the development of meters and electrical testers loaded with innovative, time-saving features.