Just squeeze the handle for a bright light without batteries!
This unique flashlight is actually an electrical generator which uses a magnetic field (and your kinetic motion) to create an electric current. A special see-through casing allows you to see the inner workings of the DYNAMO as it generates electicity.
In 1831, Michael Faraday discovered how to transform mechanical energy into electical energy using a device similar to the one in the DYNAMO flashlight.