Brunton Download is a waterproof and durable outdoor backup power device, designed with outdoor adventures in mind. It can charge phones, music players, UV water purifiers, and more while you're on the go. With a high-power USB output of 5V/2.1A, it can quickly charge your devices, even in the most remote locations. It has a rechargeable lithium polymer battery with a capacity of 4000 or 8000 mAh, so you can keep your devices powered for longer.