English: A BayGen Freeplay clockwork radio. It is powered by human muscle power and does not need batteries or recharging from mains power outlets. The radio is powered by a small internal electric generator turned by a spiral mainspring. When it runs down, the mainspring is wound up by turning the crank visible on the right hand side. The crank folds into the frame when not in use. The FreePlay was the first modern human-powered radio, and was originally designed as a low-cost radio for use in rural developing countries where electric power and batteries were not easily available.