Features: Used for microphone preamplifier, good effect, low noise and ac ripple, output signal voltage greater than 1V or greater, improve the power amplifier signal strength. Stable performance, strong signal reception. Wide voltage input, can work in long time. The amplifier board is equipped with a volume trimmer potentiometer. If you find the sound too loud or too small, you can try to adjust it. Suitable for Xiaomi balance scooter. Specification: Condition: Brand New Material: Electronic board components Color: as picture shown Power: 3W Working voltage: 5V Voltage: 5V-45V Output: Stereo 4Ω 3W Working current: 1mA (static) ~150mA (maximum) Output speaker impedance: 4Ω-32Ω (impedance high, high efficiency) Support speaker power: 0.5W-25W Size: approx. 5x3.5cm/2x1.4inch Package List: 1 x Bluetooth Board with Speaker Note: 1. The amplifier board is connected to the electret microphone by shielded cable between the ground and the amplifier board. When connected, pay attention to the polarity. When the electret is reversed, there will be little or no sound. 2. Amplifier external speaker, speaker away from the microphone to avoid noise. 3. Power amplifier board positive and negative access to 5~12V DC power supply, please do not reverse, otherwise it will burn out the module. 4. The amplifier board is equipped with a volume trimmer potentiometer. If you find the sound too loud or too small, you can try to adjust it. .