... , zero adjustment 2) 0.2%FS accuracy, RS485 ampere meter 3) CE, ISO certification 4 1/2 digital voltage meter & ampere ... and thumb switch to set High, Middle and Low alarm output value (total 3 alarm), and CT value for current input above 5A ... , users can read different value on PC, including measuring value, alarm hysteresis, transform rate, decimal point setting, communication address, baud rate ...