High Quality. Power:2.1 inference 8-24V DC power supply. Audio input: Stereo input various versions of the Bluetooth connection, using CSR8635 Bluetooth chip, Bluetooth V4.0, high software compatibility. Output Impedance:8 ohms Best (4,6,8,16 ohms impedance can diver speaker) *Output Power: Add pre-5532 output foot (powered 25V,6-ohm impedance output 2*50W, 8-ohm impedance output 2*40W dual-channel). TDA 7492 digital amplifier chip, designed to optimize the circuit layout, the sound quality is very good, big power. DIP switches can be more easily directly adjusted after-class amplifier gain, to better promote the impedance larger speakers. If you use external audio, you need to connect a 3.5mm audio line. If you directly use Bluetooth, when power, wait for 3s~10s, untilled Blue and Red light flashing alternately, then you can use your device to find my Bluetooth module, you will find “SANWU Audio “, then connect it, can directly use it. Feedback: We greatly appreciate your POSITIVE feedback. Please do NOT leave negative feedback without asking for help. Our aim is to provide Top Level Customer Service, so we will try our best to solve any problem. Thank you very much!