Features:Stereo audio, it is wide frequency response, high efficiency, low distortion and low noise, the sound effect is good.Designed with a volume potentiometer, you can easily turn the voice high and down.With power supply re connection protection,short-circuit protection and over-heat protection.Wide supply voltage and two audio input modes, more efficient.Specification:Material: circuit boardsSize: app.55 x 38 x 18cm/21.65 x 14.96 x 7.09inColor: shownQuantity: 1 PcProduct s:Product Model: XY-P40WSupply voltage: DC: 8~24VBluetooth version 5.0Connect distance: 15 meters(visible)Output mode: StereoOutput power: 20W x 2 @12V 4Ω30W x 2 @16V 4Ω30W x 2 @21V 8Ω40W x 2 @24V 8ΩSpeaker selected(40W~200W): 4Ω(5-16V supply)8Ω(5-24V supply)Operating instruction:1. Ar connecting the power supply, the blue LED is on, and it goes into Bluetooth mode, waiting for pairing ar playing the Beep;2. Turn on phone Bluetooth,"XY-P40W"will be searched and display; he "XY-P40W",it will connect to the board. It connects succefully with a Beep;3. Ar this you can play the music. The amplifier board will prepare for the pairing with a Beep.Caution:1. Keep a safe distance away from to avoid WIFI interference2. 5-24VDC is recommended; upper than 26V, it will be damaged.3. Driving 4Ω load, power supply must be under 16V; and driving 8Ω load, supply must be under 24V.4. The supply current must be 2A at least.5. The line connecting speaker with module should be within one meter.6. ESD protection, please release ESD on your hands before you contact the module.7. 40W and upper power speakers is recommended.Note:No retail package.Please allow 0-1cm error due to manual measurement. pls e sure you do not mind before you bid.Due to the difference between different monitors, the ture may not reflect the actual color of the item. Thank you!Package includes:1 x Bluetooth Amplifier Board1 x User Manuel