This is the CP2102 Breakout Board. This is a great little tool for embedded systems that require a serial connection to a computer. The board can simply attach to a USB bus via a standard type B female connector and will appear as a standard COM port.
Thes CP2102 doesn’t require any external oscillator, it has an on-board voltage regulator, and it even uses a reprogrammable internal EEPROM for the device description. The full hardware UART has flow control for baud rates from 300bps to 921600bps. This breakout also allows you to connect the TX/RX pins of your favorite microcontroller or serial application to the RX/TX pins of the breakout, creating a simple serial cable replacement.