Most life on our planet depends on light energy from the sun that comes from the nuclear fusion of hydrogen. All creatures that breath - like us - depend indirectly on this energy by consuming the biomass and the oxygen generated by plants. The evolutionary process has developed the muscle organ, which converts chemical energy into mechanical energy. Human muscles are able to deliver 100 to 200 Watts of mechanical energy, while trained top athletes can reach up to 1000 Watts for brief periods. We offer several small hand operated devices that convert human muscle energy into other forms.