Features: Precision balanced rotor, smoothness for best reliability and maximum RPM. Excellent torque and long-run times. Direct-solder wiring tabs for flexible soldering options. Dual-ball bearings design. Multiple conservation Features: Low voltage cut-off conservation, over-heat conservation, throttle signal loss conservation. For 1/8 1/10 RC car, RC boat. If there are any problems, please contact our store in time. We will give you a satisfactory solution. Specifications: Item: Motor Watts: 900W Max voltage: <13V Max Amps: 69A KV(RPM/Volt): 3900KV Max RPM: 50000 Diameter: 36mm Length: 50mm Shaft Length: 15mm Outer Shaft Diameter: 3.175mm Inner Shaft Diameter: 5.00mm Plug Type: 4mm Golden Banana Plug 45A ESC Specification: Continuous Current: 45A Burst Current: 180A Battery: 2-3S Li-Po / 4-9S Ni-Mh Ni-Cd BEC Output: 5.8V / 3A Power Supply Plug: T Plug Male Programming Card: Low voltage cut off: 3.1V/Cell 2.8V/Cell 3.3V/Cell No cut-off Start mode:Medium, soft, strong Max brake force: 25%, 50%, 75%, 100% Max reverse force: 25%, 50%, 75%, 100% Neutral range: 6%, 9%, 12%, work state Package Information: Package Size: 10*6*5cm Package Weight: 340g Plastic Package Package Listing: 1* 3900KV Brushless Motor 1* 45A Brushless ESC 1* Heat Sink 1* Programming Card