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 project. But '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 to be used with several of the available , so long as the control software supports bluetooth functionality. With this module, you 't have to plug into your flight controller with a -usb cable every time you want to 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 to find instructions and how-to's for changing the settings on the bluetooth module itself, like the 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 the antenna do not shop and alignment, it is best to hollow out. Color: As Shown Material: plastic Package Contents: 2 x Bluetooth Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.