We are offering demonstration dynamo.Demonstration dynamo : the demonstration dynamo (hand pulley) is mounted on a base plate 230 x 90mm approx. Which also carries a hand-drive pulley of 120mm dia. It is coupled to the smaller dynamo pulley by a rubber belt to give a step-up ratio.Lamp is provided as a simple output indicatorelectrical output is via a pair of 4mm socketsused motor on a 6 to 8v dc supply