Machined housing with four fan-style cooling holes that pump air through the engine while it is running. Rear threaded mounting holes with both 16mm and 19mm hole spacings fit a variety of applications. Specially designed NdFeB magnets with high temperature rating for reliable operation. High Temperature 140 Celsius (356 Fahrenheit) rated wire is used for winding the motors to minimize the risk of burning the motor. High quality epoxy coated stator plates on the inner surface to prevent winding shorts. 0.20mm stator plate is used on this 5010 motor. High quality shielded and permanently lubricated bearings are used to control the motor shaft in all motors. High temperature adhesives are used to secure stator windings and prevent shifting, pinching, or shorting. 5010 750KV High Performance Brushless Motors for MultiCopter, QuadCopter, and Multi-Axis applications. KV (rpm/v): 750KV Tooth pattern: Positive tooth ESC: 20-40A Best works with props from 14-16 inch Motor size: 50 x 10 mm Shaft size: 4mm Material: Metal Color: Silver + Black Package Contents: 1 x Set Brushless Motor 5010 750KV Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item to appear slightly different from the real thing. Measurement allowance is +/- 1-3 cm.