SMAKN&reg; Wireless Digital Bluetooth 4.0 Audio Receiver Amplifier Board TDA7492P 50W+50W 100% Brand New and High Quality . Power :2.1 inferince 8-24V DC power supply . Audio input : Stereo input various verisions 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)