Accessories and Parts -RC Model Parts Highlights Generic Brand RC Model Parts Description: Contains a variety of different types of gears, all of which can match each other The modulus is 0.5 and the inner holes are 1 .9mm, 2.05 (2.0)mm, 2.4 (2.55)mm, 2.9 (3)mm, etc. It also contains hex gears, racks, pulleys, belts, axles and many other DIY accessories. These products are for toy gear pulleys and other spare parts, suitable for DIY model technology production. It is indispensable for robots, model airplanes, cars, boats, repairing remote control airplanes/helicopters, as well as small science and technology productions. Size Chart: Packing size: 15*10*3cm/5.90x3.93x1.18inch Package includes: 106pcs plastic pieces Note: Please allow 1-3mm measurement deviation due to manual measurement. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. THANKS!