The DMS-20PC-1-LM-C is a Self-powered 3-digit LED Display AC Line Voltage Monitor for true line measurements. Screw terminals for panel mounting. Plug it into any wall outlet and instantly read voltages from 85 to 264VAC. It employs half-wave sinusoidal averaging (rms calibrated) and has a display resolution of 1VAC over its full input range. Packaged in a red-filter case with built-in bezel, the meter is fully encapsulated for ruggedness.