... frequency ranging from 15Hz to 100Hz, these meters indicate true RMS values and are substantially independent of system waveform.The ... nominal mark is T.(br). 3. Accuracy: Class 1.5.4. Specification: 30V, 50V, 75V, 100V, 120V, 150V, 200V, 250V, ... SF series is flush mounting with bracket. ......More detailed products information or have further enqiury, welcome to contact us. AC Voltage panel meter