A40 Outrunner Series A40 8L A40 10L Kv (rpm/V) 1300 1100 Max Power (W) 1100W 1100W Max Amp (15sec) 55A 55A Max Efficiency 85% 85% Io (No load A) 2.5A 1.7A Rm (Resistance) 0.014Ohm 0.019Ohm Shaft Diameter 5mm 5mm Gearbox N/A N/A Motor Diameter 41.7mm 41.7mm Motor Length 61mm 61mm Motor Weight 265g 265g Built in Fan Yes Yes Max Rpm 35,000 35,000 Poles 8 8 Case Outrunner Outrunner ESC Timing 15-20 deg 15-20 deg ESC Switching Freq. 8KHz 8KHz