Pulley Demonstration Set Demonstrate law of conservation of energy, concepts of force and mechanical equilibrium. Contains a 15x25cm wooden base with mounted capstan and a screw eye. The set has a 62.5cm vertical support rod and a 21cm crossbar with clamp, eight single pulleys, 2 double pulleys, a wheel and axle, six pulley clamps, 90° clamp, nine slotted masses ranging from 10g to 1000g, seven weight hangers, and a pulley cord.