Product_description: ['Model L21000RMV2 by Laurel Electronics is a True RMS voltmeter which includes an AC rms signal conditioner set to the 0 to 2.0000V range, 10-48 Vdc or 12-34 Vac power, and five red 14.2 mm (0.56 inch) LED digits. Five voltage ranges from 200.00 mV to 600V and four current ranges from 2.0000 mA to 5.000A are jumper selectable. This is a 60,000 count digital panel meter with exceptional performance at half the price of a bench top meter. It can measure true RMS voltage or current of AC signals where there is considerable distortion of the waveform. Fast True RMS readings in 0-16 ms after completion of one input signal cycle allow anomalies to be detected and alarmed before they become expensive problems. Fast on/off control and alarm can be achieved with optional dual or quad relays, either contact or solid state. The meter can also capture peak and valley readings that occur at the nominal rate of 50/60 Hz. AC or DC coupling is jumper selectable. Accuracy is 0.1% of full scale for signals from DC to 10 kHz, signal amplitudes down to 0.1% of full scale, and a crest factor up to 3.0. Modular architecture provides a choice of power supply boards, relay boards for alarm or control, analog output boards, and communication boards. Available communication boards include RS232, RS485, USB and Ethernet. The Modbus protocol is fully supported as is the simpler Custom ASCII protocol. Power and all inputs and outputs are mutually isolated. The meter fits in a 1/8 DIN panel cutout (92 x 45 mm) and is protected to NEMA 4X (IP65) when panel mounted. It is certified to CE, RoHS, and ETL / UL standards.'] (Page 1)