These compact, isolated USB to RS-232 and USB to RS-422, and RS-485 converters allow you to add an asynchronous serial port to your USB only PC. The built in 2 kV isolation protects your port from dangerous ground loops. They are perfect for connecting to remote devices or programming ports in field service applications. They are USB 2.0 compatible. Model USO9ML2 is the RS-232 version and supports hand shake signals as well as data at speeds up to 460.8 Kbps. Model USOPTL4 is the RS-422 and RS-485 version and supports data rates up to 460.8 Kbps. RS-485 2-Wire and 4-Wire modes are selected using a DIP Switch. If you don't need isolation, use model USPTL4. Windows operating systems up to Windows 7 (32 and 64 bit) are supported. The USOPTL4 is equipped with our signature high retention USB port. The RS-422/485 versions have a removable terminal block. Need a strain relief for your RS-422 or RS-485 cable? Check out the accessories tab for our TB5P508SR-2PK.Product Type: Data Transfer AdapterAdapter Type: Serial/USBConnector on First End: Terminal Block RS-422/485 SerialConnector on Second End: 1 x Type B Female USB 2.0 USBWeight (Approximate): 14.40 ozPackage Contents:USB To Isolated 422/485 W/Plug Term Block And Leds , 1 meter USB cable , Driver CD