This 3650 3930KV 4P Brushless Motor is built from the best materials available、 and is designed to provide both quality and performance at an affordable price. And it's with high quality aluminum alloy parts that are produced on the latest CNC milling machines. The 3650 3930KV 4P brushless will provide more power and longer run times with its high efficiency.Features:4 poles 12 slot Hi-torque motor design.CNC machined 6061 T6 billet alumium heatsink can.High purity copper windings maximizes efficiency.High RPM ABEC5 oversized bearings.Universal fit all 1/10 brushless cars-multi-mounting system for M3 screws.Precision balanced rotor、 smoothness for best reliability and maximum RPM.Stator - Super Thin (0.35mm) laminations.Removable/replaceable.Precision engineered for maximum energy conversion.Specification:RPM: 3930KVMax Current: 60AMax Watts: 820WCan Size: 3650Sensored: NoCan Diameter: 36mmCan Length: 50mmShaft Diameter: 3.175mmShaft Length: 15mmWeight: 147.8g/5.2ozMax voltage: 7.4V(2S)-11.1V(3S)Package size: 10 * 8 * 6.3cm/ 3.9 * 3.1 * 2.5inPackage weight: 178g/6.3ozNote: there's some little error from human measuring.Package list:1 * 3650 3930KV 4P Brushless Motor