Features: Made of premium material, high strength, strong structure, durable in use. Exquisite workmanship, smooth metal surface without obvious scratches. High moment of force, strong power, stable rotating speed. Compact size and light weight, low noise and stable performance. Suitable for toy car, children motorcycle, etc. Specification: Motor Model: RS550 Tooth Head Size:10*3mm, 13*3mm Voltage: 12V Revolution: 550-30000, 550-23000, 550-18000, 550-15000, 550-12000, 550-10000, 550-8000 (Optional) Motor power: 35W - 55W Motor total length: 8cm / 3.1in Motor width: 3.7cm / 1.5in Bottom diameter: 3.5cm / 1.4in Mounting hole: 2.5cm / 1in Motor shaft: 0.3cm / 0.1in Package List: 1 x Motor 2 x Tooth Head Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. Before purchase, it is necessary to verify whether the motor model and the tooth size match.