according Creative Commons licence https://www.adafruit.com/product/3309 

Long gone are the days of parallel ports and serial ports. Now the USB port reigns supreme! But USB is hard, and you just want to transfer your every-day serial data from a microcontroller to computer. What now? Enter the Adafruit CP2104 Friend!

This is a high-quality CP2104 USB-Serial chip that can upload code at a blistering 2Mbit/s for fast development time. It also has auto-reset for Arduino/ATmega328 boards so no noodling with pins and reset button pressings. The CP2104 has better driver support than the CH340 and can do very high speeds, and variable speeds without stability issues. Compared to the FT232RL and FT231X, the CP2104 has the same capabilities or better, at a great price! It even has the RX/TX LEDs to help you debug your data, they'll blink when the chip receives/transmits data.

By default, we've set it up so that it matches our FTDI cables. The 6th pin is RTS, the power wire is +5V and the signal levels are 3.3V (they are 5V compliant, and should work in the vast majority of 3.3V and 5V signal systems). Works excellently with any Arduino, ESP8266, ESP32 or any other microcontroller that uses an 'FTDI port' for communications and upload. You can also purchase a 6-pin extension cable from us, which will let you rearrange the wire order.

There's also a full collection of all the modem control pins you may need on the side, in case you need the DTR, RI, DSR, etc. pins.

Each order comes with a fully assembled and tested board. We give you a right-angle socket header and some male header strip. You can solder in the socket header on the edge to make it 'FTDI-like' or solder the male headers in to plug it into a breadboard and get access to all the pins.