It's a small USB to TTL serial tool, using the PL2303 chip.
You can use it to connect some serial device to your PC via USB port, an avr, an msp430 or an stm32 for example.
It's very cheap compared to the ft232 alternative and works very well, up to more than 1mbit/s.
This is the FPV Bracket Kit with 2 9g Servo, with the help of this product, it would be easy for you to create 3-axis projects such as environment monitoring, tracking. It would be you good partner in servo related projects.