34 kinds of gear packages, toy model gears, racks, decelerations, worms, belt wheels, plastic gears

This accessory package includes a total of 34 gears, racks, pulleys, belts and other transmission parts. The photos are taken in kind. The complete range of accessories is scientific research experiments, popular science activities, personal DIY model machinery accessories! !
The aperture of 2A is 1.95MM, 2B is 2.05MM, there are elastic collocation, some things need to be tight, and some need to be loose, which is designed in itself, not a quality problem.