Stimulate children’s imagination and creative thinking skills with this My Gears Machine Set! Children can learn the basic principles of movement and force by linking several gears together the chain to create unique and amazing machines. This set helps children practice early engineering concepts, geometry, measurement, problem-solving and reasoning. A set consists 181 pieces with 17 different shapes and instruction for 8 models. Components are compatible with 2cm linking cubes for endless creative possibilities. Size of large gears: 9cm (3-1/2"). Size of linking cubes: 2cm (3/4") L.