1. Description: This product is a stereo Bluetooth amplifier module. The Bluetooth version is 4.2. 2. Features: 1>. The version is 4.2. It can be compatible with all mobile phones and Bluetooth adapters on the market.       2>. The distance is 15 meters in open space.       3>. It supports automatically connecting devices that have been paired and playing music automatically.       4>. F class power amplifier 5W+5W, high power output, over 8002 sound quality.       5>. It supports USB sound card, no drive, plug and play.       6>. Good sound quality, suitable for upgrading and refitting the idle sound box and DIY production. 3. Instructions:       1>. Support USB sound card, free drive, plug and play (normal lithium battery power supply situation).       2>. This product has dual 5W power amplifier circuit. It can not be used in addition to the power amplifier. The output of two amplifiers can not be connected in parallel or connected to the negative electrode, otherwise the power amplifier chip will be damaged.       3>. There are two 2-8 European and 3-10W speakers respectively, and 3 European 5W and 4 European 10W horn are used. The output is stereo.       4>. Maximum working current is 5V 2A, using 5V 2A or more voltage power supply, sound quality will be better.       5>.It is suggested that a 3.7-5V lithium battery (the lithium battery needs a protective plate It can charge a lithium battery with a USB rechargeable battery, and the USB port can not be used as a power supply port.) or a 5V adapter be used for power supply. It can not use voltage and current unstable power supply, such as dry battery, portable charger, multi-function transformer and so on.       6>. When the Bluetooth board is installed, the antenna should not be close to the metal parts so as not to affect the transmission distance. 4. Operation:       Start the cell phone Bluetooth, scan the device, find the "DW-CT14+" to click connection. 5. Note: The charging interface of this product is a current limiting charging mode without charge management. For your safety, be sure to use a regular lithium-ion battery with a protective plate, which can cause loss due to improper use. 6. Package list: Main board + plug line