Key Features Compatibility: Universal support for devices capable of charging via USB port. Additionally, the wired Fast Charge feature is compatible with the Samsung Galaxy S6, Galaxy Note 4 and later models of the Galaxy S and Galaxy Note series. Take high speed charging technology on the go with the new 5100mAh Fast Charge Battery Pack. Available in black or silver, this battery pack allows you to charge devices compatible with Samsung Fast Charge at a much faster rate than traditional USB charging options. With a universal USB port output, you can charge other smartphones, tablets or other electronics capable of charging via USB at standard charging rates. The battery pack’s 5100mAh capacity can be recharged over and over. When fully powered, the battery pack holds enough juice to charge most of the latest smartphones up to at least 1 ½ times.Pass Through Charging Charge the battery pack and a device connected to the battery pack overnight with pass-through charging. When a device is attached to the battery pack and the battery pack is being charged from a power outlet, the device will be charged to 100% first and then the battery pack will begin to charge.Easy to Use To begin charging, plug in a USB charging cable like the included USB to Micro USB charging cable to the USB output port (larger rectangular port) on the battery pack and connect the opposite end of your charging cable (whether Micro USB or other) to your smartphone, tablet or other electronic device. Your device will immediately begin to charge. For recharging the battery pack itself, plug a Micro USB charger into the Micro USB port of the battery pack.Safe Charging Official Samsung lithium ion batteries are built-in to ensure an optimal charging experience for a range of Samsung or non-Samsung devices.Status Monitoring The Fast Charge Battery Pack has 4 LED indicators that display remaining charge when the status button next to the light is pressed. The LEDs also light up when the battery pack is charging and blink to indicate how close the battery is to being fully charged.