The TTL-232R cables are a family of USB to TTL serial UART converter cables incorporating FTDI's FT232RQ USB to Serial UART interface IC device which handles all of the USB signalling and protocols.

These cables provide a fast, simple way to connect devices with a TTL level serial interface to USB. 

Each TTL-232R cable contains a small internal electronic circuit board, utilizing the FT232R, which is encapsulated into the USB connector end of the cable. 

The FT232R datasheet, DS_FT232R, is available at HTTP://www.ftdichip.com.  The other end of the cable comes with a selection of different connectors supporting various different applications. 

This TTL-232R-AJ cable is supplied with a USB connector on one end and a 3.5mm audio plug on the other end.