Power Input: Micro USB interface for power charging. Power Output Interface: Standard USB Type-A interface for charging other devices. Charging Interface: Use the included 3.5DC output line and Micro USB adapter to charge the wireless charger or power devices via USB charging on the computer. Charging Indicators: The indicator displays the current power level of the power bank. Initial Charging: When using for the first time, or after long periods of inactivity, activate the mobile power charging three times before charging to its full capacity, which takes about 20 hours. For best results, charge for only 8 hours before use, as this allows the battery to reach its optimal power state. Digital devices, including smartphones, compatible with 5V (DC) input voltage can be charged by this product. A red indicator light indicates that the connected device is being charged. Once the device is fully charged, the indicator light will turn off.