Handcrafted from durable hardwood, these engaging models are designed to show the operation of a particular device. Each student-sized model includes an activity guide detailing the history of the model, practical applications and classroom experiments. Models measure 6"-18" and are excellent for small groups or individual study. Set of 12 includes: • Inclined Plane • Lever • Gear Rack • Wheel & Axle • Screw • Pulley • Motion Converter • Fulcrum Balance • Gear Train • Pendulum • Block & Tackle • Wedge