Features 1.Dual Channel: The stereo sound of this Bluetooth power amplifier board is output by dual channels, ensuring continuous serial high power operation. 2.High Compatibility: The audio input of this power amplifier supports Bluetooth, AUX, USB flash disk, USB sound cards. 3.APP Function: Support for Wuzhi Audio APP function, you can change the Bluetooth name and set the Bluetooth password, adjust the volume of beep and switch sound, play sleep aid and timer shutdown, also can do the sound effect adjustment, USB flash disk selection and playlist. 4.Treble And Bass Control: This Bluetooth power amplifier board can change the inherent high and low tones, just use the treble and bass control knobs and it will give you the feeling of being in a cinema. 5.Security Preserve: This amplifier board has input protection against reverse connection, overheating, overcurrent and short circuit. Specification Item Type: Bluetooth Power Amplifier Board Material: PCB Model: ZK TB21S Power Amplifier Chip: TPA3116D2 Number Of Channels: 2.1 channels (left channel and right channel and subwoofer) Input Method: AUX and Bluetooth and USB flash disk and USB sound card Bluetooth Version: 5.1 Switching Method: Mechanical switch (no need to wait for a long press) Voltage: DC12 to 24 V, ≥8A Speaker: Left and right channel 20 to 50W, 4 to 8Ω; subwoofer 20 to 100W, 3 to 8Ω Output Power: Left and right channels ≤ 50W, subwoofer ≤ 100W Protection Mechanism: Input antireverse connection, overheating, overcurrent, short circuit protection Package List 1 x Bluetooth Power Amplifier Board 1 x Power Connector Fitting 5 x Knob 2 x Protective Case 9 x Screw 8 x Nut