The module is a portable backup power supply with an input that matches the 5.0V adapter to charge the internal battery. Use built-in battery for portable device to provide 5.0V/3.0A USB2.0 supply output for external devices. Dual USB 5V 2.4A: Equipped with dual USB 5V 2.4A ports, it provides versatile charging options for your mobile power bank or 18650 charging module circuit. LED Indication: The built-in LED indicator provides real-time charge status, adding convenience and safety to your charging experience. Button function: Press and hold the button after standby, the LED digital screen displays the power.Note: The positive pole of the battery is connected to B+ and the negative pole is connected to B-, do not reverse it. If it is reversed, it will burn out! Dual output current: 5V 2.4A; Input voltage B+ to B-: 3.0 - 4.2V; Protection: overcharge protection, overdischarge protection, short circuit protection, constant current. IR of PCM: ≤65 mΩ Allowed 0V change: Yes Constant current: 2.4A Dual output current: 5V 2.4A Input voltage B+ to B-: 3.0 - 4.2V Charging cable: support three type of USB Cables for Apple interface & for Android Type-C Micro-USB Button function: Press and hold the button after standby, the LED digital screen displays the power Prevent Overcharge Protection Detection voltage: 4.20±0.05V Release voltage: 4.100±0.05V Detection delay time: Less than 200 ms Prevent Overdischarge Protection Detection voltage: 3.0±0.10V Release voltage: 3.10±0.10V Detection delay time: Less than 100 ms The printing/appearance may vary from batch to batch, but it will not affect the use; the actual product may have color difference due to different light or display. Colour:Green Material:PCB+Components Package Contents: 3 x Battery Charger Board Only the above package content, other products are not included.