With this USB to TTL adapter, you can establish communication with your board/MCU via your computer. Maximum transmission speed up to 900K. The main chip is FT232RL from FTDI, high stability. LED indicator for TX, RX, Power supply. It is very useful when you debug or download. PIN definition: CTS, RTS, RXD, TXD, GND, VCC, support 3.3V and 5V VCC outputs, switch by jumper. Works with Windows 10, 7 (32/64bit) Vista 2008, XP, 2003, Mac, etc. WARRANTY: We support this FDTD USB to TTL converter with 12 months warranty. If you meet any questions, please contact us.