Encoder gear electronic starter set for DC motors, designed for easy installation and reliable use in small mechanical and robotics projects. Key benefits Simple to install and store, reducing setup time for prototypes and hobby builds. Compatible with common low voltage DC systems, providing flexibility across projects. Compact dimensions and precise speed options allow predictable motion control. Store in an airtight bag when not in use to prevent moisture and rust. Specifications Wheel diameter: about 44 mm Shaft diameter: about 3 mm Voltage: DC 3V, 6V, 12V Speed options (RPM): 15, 30, 50, 60, 100, 200, 300, 400, 500, 600 Finish: fine workmanship for consistent performance Package contents: 1 set x encoder gear electronic starter Performance and compatibility Works with small DC motor assemblies that accept a 3 mm shaft and run at 3V, 6V, or 12V. Multiple RPM choices support slow, precision movement or faster rotation as required by the application. Compact 44 mm wheel diameter fits many hobby frames and chassis. Practical use scenarios Robotics projects: integrate as a wheel or encoder gear for wheeled robots and motion control experiments. Solar or battery powered vehicles: use for drive or transmission testing on small scale cars. Small windmills and fans: apply for educational models and airflow testing where selectable speeds are needed. Additional notes Allow a measurement tolerance of 15 mm due to manual measurement. Item color may vary slightly from photos because of monitor differences. Easy to install and easy to use, suitable for hobbyists, students, and prototype builders.