Jrelecs 3674 1900KV 4 Poles Sensorless Brushless Motor for 1/8 Monster Truck RC Car (3674 1900kv) Hi-torque and hi-efficiency, Removable/Replaceable rotor High RPM ABEC5 oversized bearings, High purity copper windings maximizes efficiency CNC machined 6061 T6 billet aluminum heatsink can, Precision engineered for maximum energy conversio Precision balanced rotor,smoothness for best reliability and maximum RPM, Universal fit, fits all 1/8 brushless cars-multi-mounting system for M3 screws 3674 1900KV sensorless brushless motor is designed to provide both quality and performance at an affordable price. It is built from high quality aluminum alloy which is produced from the latest CNC milling machines, and is designed with high power and rotation speed to provide longer run time.