Power amplifier board size: 7.1x4.3CMFixed hole distance: 6.6x3.8CMBluetooth 5.0, support serial port to change the name and passwordSupport button shutdown / boot, support serial port to change the tone volume and off, support call off, power on, default volume maximumTX, RX, GND: TTL serial port configuration 9600, N, 8, 1Output maximum power 2x15W at 16V 4AOutput maximum power 2x10W at 12V 4ADC8-22V power supply with reverse connection protection, support for laptop power adapterM+ and M- are the positive and negative poles of the microphoneColor as shownMaterial: PC+MetalPackage Contents:1 x Audio Amplifier BoardOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.