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 trouble-free 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 engine. High quality shielded and permanently lubricated bearings are used to control the motor shaft in all of our motors. High temperature adhesives are used to secure stator windings and prevent them from shifting, pinching, or shorting. 5010 360KV High Torque Brushless Motors for MultiCopter, QuadCopter, and Multi-Axis Aircraft. KV (RPM/V): 360. Anti-tooth design. ESC: 20-40A. Best performance with propellers from 14 to 16 inches. Shaft size: 4mm. Engine size: 50 x 10mm. Material: Metal. Color: Silver + Black. Package includes: 1 x set Brushless Motor 5010 360KV. Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual item. Measurement may vary by +/- 1-3cm.