Features: RS232 system communication serial port optic isolation product Suitable for terminal devices using 3 wire system (TXD, RXD and GND), such as modem, router, multi-user system and satellite receiver, etc. Protects against the effects of electrostatic discharge, faulty wiring and lightning Support RS-232 asynchronous communication standard, direct insert into RS-232 interface serially, convenient operation For added convenience, the DB-9's male/female genders are reversible with the included thumbscrews for Why take a chance on blowing up your COMM PORT this simple device will protect your PC and RS232 devices, when plugging into an unknown device or plugging into one that has a short you can damage your comm port in a hurry! This DTECH RS232 Optic Electric Isolator is designed to protect the RS232 serial interface at both ends of the device, inhibit static and surge, prevent ground loop and surge damaging devices. Connection: 9 pin DTE devices transmit on pin 3 and receive on pin 2 9 pin DCE devices transmit on pin 2 and receive on pin 3 Specifications: Optic electric isolation voltage: Instant 2.5KV rms; Continous 500V DC Transmission Rate: 300 bps - 57600 bps Power: Port powered, Supply from RS232 (one of TXD / DTR / RTS) Quantity: 1 Pc Note: Please allow 0-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1 x DTECH RS-232 Optic Electric Isolator