Spektrum Firma 4000Kv Brushless MotorScale: 1/10Kv: 4000Voltage: 2s#of poles: 4Length: 2.0in (52mm)Width: 1.4 (36mm)Weight: 210g (7.4 oz)Wire length: 4.72in (120mm)Shaft diameter: 1/8 (3.175mm)