This IDEAL TL-532A Analog Voltage Detector Meter is used for real-time TRMS voltage, frequency, and harmonics monitoring. It logs voltage, sags, swells and impulses. It will measure % THD and logs periods of 3% (line to neutral). There are selectable thresholds based on the most accepted international standards that will default to ITIC.It has custom programmable event thresholds with invertible display for when it is necessary to plug it in upside down. It is rated for CAT III 300V and will save up to 512 events with a 2-year warranty. J.Walter Becker founded IDEAL in 1916 and made a promise that is still an important part of the way IDEAL operates today: "An IDEAL product will provide a value greater than the price paid for it. Service is a part of the product." IDEAL brings you products that make your job easier; products that you can rely on, with warranties you can trust. Every IDEAL product comes with the promise made by our founder more than 90 years ago.