Features: Output power 6W + 6W dual channel stereo. Supply current: enough power of 1A or more. (Power supply is not enough, the volume will generally appear outside the assembly phenomenon.) Applicable speaker impedance: 4 ohms, 6 ohms, 8 ohms (speaker impedance is too small will have the volume to open a large sound phenomenon. Power supply voltage: 5V DC or 3.7-volt lithium battery.(used in the battery is too long battery voltage is too low will have a little volume to open the big sound phenomenon) Bluetooth power amplifier standby standby small stereo sound quality is better for small Bluetooth speakers use. Charging interface: the use of lithium battery power supply, the charging interface 5 volts power supply or mobile phone charger can charge a single lithium battery.(Charge management circuit on the battery limit the maximum voltage of 4.2VDC) Specification: Material: ABS Model: Bluetooth power amplifier board Type: Other IC Power: 2x6W Application: Audio Featured Service: It can be connected to lithium battery Package List: 1 x Bluetooth Power Amplifier Board Note: When the sliding switch ON Micro USB port is the charging port, powered by the lithium battery to work, slide the switch OFF when the Micro USB port is the power supply port, you can not take lithium battery work. 1、Charging interface: the use of lithium battery power supply, the charging interface 5 volts power supply or mobile phone charger can charge a single lithium battery.(Charge management circuit on the battery limit the maximum voltage of 4.2VDC) 2、Supply current: enough power of 1A or more.(power supply current is not enough to use the volume of the General Assembly will appear off the phenomenon) 3、Applicable speaker impedance: 4 ohms, 6 ohms, 8 ohms (speaker impedance is too small will have the volume to open a large sound phenomenon. 4、Power supply voltage: 5V DC or 3.7-volt lithium battery.(used in the battery is too long battery voltage is too low will have a little volume to open the big sound phenomenon) 5、Bluetooth power amplifier standby standby small stereo sound quality is better for small Bluetooth speakers use.