Feature: 1. Aluminum Material: Made of high quality aluminium alloy material with high strength, durable, wear resistant, long service life, improving your using experience. 2. Easy to Use: Manufactured with accurate shape and size, has a close fitting for use, simple for installation and removal without complex steps. 3. High Accuracy: Made with high processing accuracy, which makes the adapters stable and reliable for installation, strong for heavy duty work and preventing deformation. 4. Easy to Use: Can be used to replace the original damaged or worn parts to provide long life and better performance, enhance the overall performance of RC motor. 5. Package Content: The package contains 3 adapters, 3 set screws and a right angle wrench, convenient for you to install and use the accessories. Specification: Item Type: Motor Shaft Pinion Adapter Material: Aluminum Alloy Color: Silver Application: For RC Motor 3650 550 540 Pinion Gears Product Size: Outer Diameter: Approx.5mm/0.2in Inner Diameter: Approx.3.175mm/0.125(1/8) Inch Height: Approx.12mm/0.5in Weight: Approx.5g/0.2oz. Package List: 3 x Adapter3 x Set Screw1 x Right Angle Wrench