1FUNCTION: BT module can be used with cell phone APP to realize the functions of wireless monitoring, parameter design and data viewing, with simple settings. 2HIGH PERFORMANCE AND LOW POWER CONSUMPTION: Adopting high performance and low power BT special chip to bring you a good using experience. 3ADVANCED TECHNOLOGY: This BT module adopts the latest BT technology and BLE technology, featuring fast communication and strong anti interference ability. 4POWER SUPPLY: This BT module does not need to use external power supply, power supply directly from the RJ12 communication port power supply, very convenient. 5COMMUNICATION DISTANCE AND APPLICABLE MODELS: The communication distance of this BT module is up to 15 meters. And this BT module is suitable for ML series MPPT 20A 30A 40A 60A solar charge controller.