Allows your device to both send or receive the TTL data via Bluetooth technology without connecting a serial cable to your computer. This bluetooth bluetooth is perfect for adding bluetooth functionality to your arduino project. But don't think that it is limited to just being used there. Another use you will find for this bluetooth module is with your flight management controller on your quadcopter. It should be able to be used with several of the available options, so long as the control software supports bluetooth functionality. With this module, you don't have to plug into your flight controller with a micro usb cable every time you want to tweak something, upload a new configuration, or check data. So long as you are within range,youI can connect to it through bluetooth instead. There is even an android version of your flight controller software so you can do everything from your phone and not have to carry a laptop with you. Do some googling and you should also be able to find instructions and how-to's for changing the settings on the bluetooth module itself, like the name it uses to identify itself and the pass code for pairing it with devices, along with enabling and disabling different bluetooth protocols.Note: 1.SPP-CA Bluetooth module serial port level to 3.3V, if connect 5V level,the system needs to increase the level conversion chip. 2.The Bluetooth signal is greatly affected by the surrounding, such as trees, metals, walls and other obstacles will have a certain Bluetooth signal absorption or shielding, we advise do not installed in the metal shell. 3.Due to the metal will weaken the antenna function,we advise when you lay board for the module, the module below the antenna do not shop and alignment, it is best to hollow out.Package included: 2 * HC-06 RS232 4 Pin Wireless Bluetooth Serial Transceiver Support Module