Medis Power Pack Universal Replacement Fuel Cell (Black) The world?s first personal, portable, fuel cell power system for always-ready, instant power without outlets or traditional batteries Small, lightweight, easy to use, and safe ? UL and CE approval plus Department of Transportation permit ideal for use on airplanes, travel, emergencies, outdoor activities, and more Green, clean, alternative energy source ? It?s one of the greenest sources of backup power in the world and it?s recyclable Plenty of power - 20 Watt-Hours on tap -- good for multiple charges of most phones and other portable electronics Refill only for Medis Xtreme and the Medis Emergency Kits sold separately