DTECH Port Powered RS232 to RS232 Serial Port Optic Electric Isolator to protect you PC and RS232 Device 9 pin male to female converter - RS232 system communication serial port optic isolation protector product Mini RS232 opto isolator is suitable for terminal devices using 3 wire system (TXD, RXD and GND), such as modem, router, multi-user system and satellite receiver, etc RS232 isolated interface adapter protects against the effects of electrostatic discharge, surge, faulty wiring and lightning Bus-powered serial optocoupler supports RS-232 asynchronous communication standard, direct insert into RS-232 interface serially, convenient operation For added convenience, the DB-9s male / female genders are reversible with the included thumbscrews