After receiving the Bluetooth board, refer to the wiring diagram to solder the speaker and 3.7V lithium battery, and then check that the battery is not connected reversely. Turn on the power switch. The blue indicator light should light up. If it does not light up, quickly turn off the power to check whether the battery is installed correctly. When the indicator light is on and there is an audible prompt sound, turn on the mobile phone Bluetooth to refresh the device name. Find DAU Audio to connect and play music on the mobile phone. Regarding TWS pairing, if you buy two DAU Audio Bluetooth modules, they can be paired in stereo. Turn off the Bluetooth on your mobile phone first, then turn on both boards at the same time. Wait for a few seconds to hear the prompt tone. Then the blue indicator light of one module will stay on, and the indicator light of the other module will continue flashing, indicating that TWS pairing is successful. Then turn on the mobile phone to connect Bluetooth, and you will have a stereo wireless speaker. It is recommended to use a 500mAh-2000mAh capacity 3.7V lithium battery, and a 5V 1A-2A charger, using a USB 2.0 to Type-C cable for charging. Working voltage: DC3.5V-5V. Speaker: 2-4 ohms (3W-10W), can connect one 2 ohm speaker or two 4 ohm speakers at the same time. Charger: 5V/1A is recommended. Charging interface: Type-C. Headphone jack: 3.5mm. Battery: 3.7V polymer lithium battery or 18650 lithium battery (customers need to prepare their own batteries). Size: 28.5mm x 17.3mm. This is a DIY kit that requires finishing by yourself. Different batches may have different printed words, which will not affect the use. Color: Purple. Material: ABS. Package Contents: 5 x Mono amplifier decoding boards.