Features High-quality and durable: Made from premium plastic material, our gear set ensures excellent wear resistance and a long service life. Perfect for DIY enthusiasts: Designed as spare parts for toy gears, this set is ideal for anyone engaged in DIY model technology production. Versatile usage: These small and easy-to-use gear parts are fantastic accessories for a wide range of projects, such as building cars, robots, and more. Multiple gear options: Our gear set includes 19 different gear parts, providing you with various options to meet your specific DIY need Easy to understand: For instance, 16102B signifies a gear with 16 outer teeth, 10 inner teeth, an aperture diameter of approximately 2mm, and suitable for a 2mm loose-fitting shaft. Description: If you are a model amateur, you would know that gears are essential and necessary parts for models. Aircraft, automobiles, boats, robots and other small production of science and technology will all need to use gears. Here we provide 19pcs gears of different sizes which may meet your basic needs for model making. They are also good replacement parts of old or broken gears. Specifications: Material: Plastic Color: White Modulus: 0.5 Thickness: 4~5mm Type:  16102B, 18102A, 20082B, 20102B, 22082A, 22102B, 24102B, 24122B, 26082B, 28102B, 30122B, 30162A, 32082B, 34102B, 38082B, 40102B, 46082A, 48102B, 50102A 1. The first and second number is outer teeth number 2. The third and fourth number is inner teeth number 3. The fifth number is aperture diameter 4. 2A means center shaft is 1.95mm and close-fitting with 2mm shaft. 2B means center shaft is 2.05mm and loose-fitting with 2mm shaft. 5. Gear outer diameter=(teeth number+2) x 0.5mm e.g. 16102B means 16 outer teeth, 10 inner teeth, aperture diameter is about 2mm and loose-fitting 2mm shaft. Gear outer diameter=(16+2) x 0.5mm=9mm. Weight: 9g(approx.) Package Includes: 19pcs x Gears Package List