Come on baby light my shower ... with the techie water powered shower light. Water enters the shower head through the flow resrictor (1) then travels through the injector plate (2) which directs the water to the waterwheel (3). The water spins the magnetic waterwheel past the stator (4) of the field wincing (5). This hydroelectric generator develops the 2.5 volts at .31 amps which lights the PR-6 bulb. More here ...