The FTDI cable is a USB to Serial (TTL level) converter which allows for a simple way to connect TTL interface devices to USB. The VCC pins of this FTDI cable are configured to operate at 5V with 3.3V I/O.

The FTDI cable is designed around an FT232RQ, which is housed in a USB A connector. The other side of the cable is terminated with a 0.1" pitch, 6-pin connector with the following pinout: RTS, RX, TX, 5V, CTS, GND (RTS is the green cable and GND is black)