The TTL to USB board provides an interface between a PC USB port and a UART serial interface. It can support any interface voltage between 1.8V and 5.25V. It uses the FTDI FT230XS chip. It supports TxD, RxD, CTS, and RTS signals. It has a power connector for 5V and 3.3V power if the board you are interfacing to is unable to provide power.
More information is available at the designer's page.