Portable power pack dual usb charger battery capacity 3 500 mah interfaces usb microusb power output max 1 dimensions 110 x 61 x 8 6 mm features battery indicator included in delivery micro usb cable user manual colour black rechargeable battery technology li polymer output voltage 5 v operating voltage 5 v material aluminium charging function charges 2 devices simultaneously applications smartphone camera mp3 player securities overcharge protecti