The pocket-sized HandEnergy device uses your hand to generate power to charge mobile devices. That’s right, simply hold it in your hand, rotate your wrists, and the two-axis rotor gyroscope will do the rest. To be more specific, users wind a starter ring, which then transmits a signal to activate the rotor, causing it to spin at an average speed of 5,000 rotations per minute, thus creating an electric current to charge its integrated batteries. Continue reading for another video and more information. Click here for a few bonus images of things you might want, but probably don’t need.

“We don’t necessarily think this will be something that you use every day, because it takes around one hour to reach full capacity. But it’s small enough to fit in your pocket, and you can use it anywhere if you find yourself someplace with no plugs or available electricity,” said HandEnergy co-founder Alex Novik .