Hailing from the future, Brunton’s Hydrogen Reactor Portable Power Pack is the next gen environmentally friendly generator that fits in your pocket. It works by combining hydrogen from rechargeable hydrogen cells with oxygen from the atmosphere to produce 2 amps of electricity (more than your typical USB 2.0 port) with no harmful chemicals or byproduct. In a 8.5 oz (242 g) in a thin 5.3 by 2.9 inch package, this pocket generator is perfect for all your backcountry or emergency electricity needs. Additional hydrogen cells are purchased separately. $149.99