Optical isolation protects your devices from transient surges and ground loops on your data line. Model 232OPDR isolates four RS-232 data signals. LEDs indicate data transmission and power-on. Requires external power supply not included.- Terminal Block Connectors for RS-232- Wide temperature range (-40° to +80°C)- Wide power range (10-30 VDC)- MODBUS compatible- DIN Rail mount- 2000 volts optical isolation- UL Recognized- FCC Class B- CE