This lead contains the PL-2303HX 04223A chip.
The PL-2303HX is a low cost and high performance USB-to-Serial Bridge Controller. The PL-2303HX provides a convenient solution for connecting an RS-232 full-duplex asynchronous serial device to any Universal Serial Bus (USB) capable host. The PL-2303HX highly compatible drivers could simulate the traditional COM port on most operating systems allowing the existing applications based on COM port to easily migrate and be made USB ready.
Details here:
http://prolificusa.com/portfolio/pl2303hx-rev-d-usb-to-serial-bridge-controller/
https://cdn-shop.adafruit.com/datasheets/PL2303HX.pdf
http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=225&pcid=41
Suitable for use as USB to RS232 TTL PL2303HX Cable Converter Module Arduino Raspberry Pi Atmega