Feature: 1. [2 Control Ports] The PCB board reserves 2 control ports, one is to output high level first, and then output low level when power on or pause. The other one is to output a low level first, and then output a high level when it is turned on or suspended. 2. [Good Transmission Effect] The power amplifier board uses Bluetooth 5.0 main control chip, which has good transmission effect and high stability. This is for professional users to use external power amplifier DIY, ordinary users do not need to use it. 3. [With Button Control] With button control, it can control up and down songs, volume addition and subtraction, play, pause, switch on and off, etc., and reserve high and low level control interfaces, regardless of daily use or DIY modification, with strong playability. 4. [Output Interface and Power Interface] Power Interface: Powered by micro 5p interface, ordinary mobile phone charger charging cable can be used. (reserved 2.5mm welding port, does not support battery power). Output Interface: 3.5mm Stereo (reserved welding point, you can DIY). 5. [Practical Use] The Bluetooth signal of phone, laptop, and tablet can be transmitted to power amplifier, active speaker and other device. The interface can also be connected to 3.5mm headphones to turn into Bluetooth headphones. (without mic, voice chat is not supported) Specification: Item Type: Bluetooth Receiver Board Material: PCB Colour: Black Bluetooth Version: V5.0 Transmission Distance: About 10m / 33ft (the shorter the distance, the better the stability) Output Interface: 3.5mm Stereo (reserved welding point, you can DIY) Power Interface: Micro 5p (reserved 2.5mm welding port, does not support battery power) Input Voltage: 3.7V-5V SNR: 90dB Total Harmonic Distortion +Noise:-70dB Crosstalk: -86dB DNR: 91dB Transmission Protocol: A2DP/AVCTP/AVDTP/HFP. Package List: 1 x Bluetooth Receiver Board