This product is a 5.2 BT pair box function (two modules) the voltage is 5V or current is 2a, the power supply is processed by secondary development of peripheral hardware, the maximum power can be configured to 5W, and the BT device name is ymx-868bt Power supply: DC voltage (3.7-5v), current should be more than 1.5a-2a USB is the charging input port 5V in can be charged from here the red light is on when charging, but the red light is not on when fully charged). Please choose the lithium battery with protection board please choose the original manufacturer for the charger, Shanzhai not only can't keep up with the current, but also can't keep constant current, which is easy to damage the battery and board. Pay attention! If the function is used, two BT modules must be used when the is connected to one board, it is mono when the is disconnected, it is stereo Special attention: 1. Bat and is connected to the positive pole dc3.7v to 5V and, GNT - is connected to the negative pole 2. The working voltage of lithium battery is 3.7V, or the DC of regulated power supply is 4.5-5v, and the current is 600-700ma when one horn is connected about 1.5-2a when two horns are connected. The lithium powered horn is equipped with 4 Ω 3W and 3W, the regulated power 5V horn is equipped with 4 Ω 5W and 5W. If the current is not enough, there will be some bad phenomena, such as skipping or BT instability, main board restart all the time or poor sound quality or broken sound or distortion (if there is such a problem, please check your power supply) the voltage should not be higher than 5V, otherwise the main chip, power amplifier IC and related components will be damaged, please pay attention 3. Horn wiring: white 2p seat SP - or SP and from bottom to top, l-o - or l-o and connected to horn 1 white 2p seat SP - or SP and from bottom to top, R-O- or R-O and connected to horn 2 color:As shown Material:PCandMetal Package Contents: 1 x Audio