With this USB to TTL adapter, you can establish communication with your board/MCU through your computer. Maximum transmission speed up to 3Mbps | The main chip is FT232RL from FTDI ,High stability. LED indicator for TX,RX,Power,It is very useful when you are debugging or downloading. | Pin Definition: CTS,RTS,RXD,TXD,GND,VCC;Support VCC output 3.3V and 5V, switch by jumper. | Works with Windows 10, 7(32/64bit) Vista 2008, XP, 2003,Mac Etc. | WARRANTY:We back this FDTD USB to TTL Converter with 12 months warranty.If you meet any question, Please contact us, We will fix your issue within 24 hours.