Hobbywing 90070010 Seaking 3900KV 2848SL Brushless Motor Water cooled motor ideal for boat application. Spec Check: Poles: 2 Lipo: 2S-3S kv: 3900 Max Current (A) / Max Vol (V): 41A /12.6V No Load Current (A) @ 7.4V: 2.4A Resistance: 0.0155 Diameter: 27.8mm Diameter of water cooling pipe: ?5mm Length (without Shaft): 48mm Shaft Diameter: 3.175mm Shaft Length: 12mm Weight: 135g