Feature 1 35mm standard DIN rail installation, complying with standard DIN EN50022. 2 Ten pole width, complying with standard JB/T71211993. 3 Standard configuration 5+1 digits display (99999.9kWh) by step motor impulse register. 4 5 LED instructions respectively power supply state (phase voltage A,B,C) and REV. signal of closed energy impulse. 5 Automatic detection the direction of the flow of load current. And instructions (signal of closed energy impulse is green when working, that is meaning the direction of the flow of load current reverse). Features: 35mm standard DIN rail installation, complying with standard DIN EN50022. Ten pole width, complying with standard JB/T7121-1993. Standard configuration 5+1 digits display (99999.9kWh) by step motor impulse register. 5 LED instructions respectively power supply state (phase voltage A,B,C) and REV. signal of closed energy impulse. Automatic detection the direction of the flow of load current. And instructions (signal of closed energy impulse is green when working, that is meaning the direction of the flow of load current reverse). Single direction 3 components measure 3 phase 4 wire active energy consumption. It is nothing with direction of the flow of load current. Complying with standard IEC 62053-21. Standard configuration short terminals cover, may select extension terminals cover, in order to protect to use safety. Specifications: Model: XTM1250S-U Accuracy: Class 1 Working Voltage: 3x220V/380V Current: 10(40)A ,15(60)A (Optional) Insulation performance: AC voltage 4kv for 1 minute,1.2/50us waveform impulse voltage 6kv Size: as the picture Weight: 503g Package included: 1 x DIN-Rail Electric Meter 1 x Manual