Frequency Meter Platinum Series  120V AC Input Scale: 55-60-65hz  High-quality range of Switchboard Instruments with class 1 accuracy, complying with American ANSI-C39.1(1981) Specifications. Available in 4 case sizes, their rugged design characteristics meet the needs of the most demanding environment applications. This extensive range of analog meters provides 1% accuracy for all AC & DC ranges.