Feature: Using Bluetooth-compatible 5.0 main control chip, good transmission effect and high stability With button control, there are control up and down music, volume increase and decrease, play, pause, switch machine, etc., The micro 5p interface is powered, and the ordinary mobile phone charger 5V2A charging cable can be used. Specification: Audio parameters: 4 ohms 2x5W Power interface: micro 5p (reserved 2.5mm welding port, does not support battery power supply) Input voltage: 3.7V-5V Power amplifier working mode: switchable AB and Signal to noise ratio: 90DB THD+N: -70DB Crosstalk: -86db DNR: 91db Transmission protocol: A2DP/AVCTP/AVDTP/HFP Transmission distance: about 10 meters Output interface: 3.5mm stereo (reserved welding points, can DIY) Speaker output port*2 groups (one set for each of the left and right channels), and the headphone jack cannot be used at the same time. When the headphone jack is connected to the headphone, the device will automatically switch to the headphone output and stop the signal from the speaker output port of the power amplifier board. Product size: 70*30*15mm/2.75*1.2*0.6in Product weight: 17g Packing size: 80*50*20mm/3.15*1.9*0.8in Package weight: 19g Color: Black, Blue Product use: Bluetooth-compatible audio signals of mobile phones, laptops, and tablets can be received through this Bluetooth-compatible to the stereo amplifier output. The audio interface can also be connected to ordinary earphones with 3.5mm interface, which can turn ordinary earphones into Bluetooth-compatible earphones (without microphone, Does not support voice chat) Package include: 1Pcs Board Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you Please allow 1-2cm measuring deviation due to manual measurement.