ITEM NAME:2 x CT14 Mini Stereo Bluetooth 4.2 Power Amplifier Board Module + Wire New Descriptio n Material: FR4 Size: 40*20*12MM wire length: 20cm Packing :2pcs bluetooth power amplifier audio module + wire Warning: The charging interface of this product is current limited charging mode without charging management!For the safety of your life and property, please be sure to use regular manufacturers with protective plate lithium battery, if improper use of losses, the company does not assume any responsibility! Note: This product will automatically shut down after 10 minutes in standby mode. It needs to be restarted. Bluetooth module operation: open the bluetooth of the mobile phone, scan the device, find "dw-ct14 +" and click to connect. This bluetooth is version 4.2.Compatible with all mobile phones and bluetooth adapters on the market.The open ground transmission distance is about 15 meters.Support auto-back to paired devices and automatically play music. Instructions: 1. Bluetooth version 4.2. 2. Support USB sound card, drive free, plug and play (normal lithium battery power supply). 3. This product has been equipped with a dual 5W power amplifier circuit. Do not connect to another power amplifier!The output of two power amplifiers cannot be connected in parallel or the negative poles together, otherwise the amplifier chip will be damaged. 4. Can connect two speakers of 2-8 euro, 3-10w respectively, push use 4 euro 5W and 4 euro 10W speakers. Output is stereo. 5. The maximum working current is 5V2A, and the stable power supply of 5V2A or above can provide better sound quality. 6. 3.7v lithium battery is recommended (lithium battery should have protective plate!)With USB charging port for lithium battery charging,USB port can also be used as a power supply port or 5V adapter power supply. 7. When the bluetooth panel is installed, try not to get close to the metal parts, so as not to affect the transmission distance. Whatever the ending's perfect or not, you can't .This product has been equipped with a dual 5W power amplifier circuit. This bluetooth is version 4.2. Bluetooth version 4.2. Output is stereo. Size: 40 20 12MM wire length: 20cm. We want to make sure you are happy with our item.