The brushless motor is designed for 450 class electric helicopters, offering excellent performance for 3D flying. Suitable for 3-4S Li-Po batteries, it delivers 4000 RPM per volt with a no-load current of 0.5A at 10V. Maximum efficiency current ranges from 8A to 10.5A, with over 75% efficiency. Continuous current capacity is 40A for up to 60 seconds. Recommended for 450 class electric helicopters and direct drive setups with 6 to 8 inch propellers. Shaft diameter: 3.17mm. Motor dimensions: 31x29mm. Constructed with metal materials in green color. Package includes: 1 x motor. Other items not included. Note: Lighting and display differences may cause slight variations in color between the image and actual product. Measurement tolerance is +/- 1-3cm.