Micro Outrunner Motor 4500KV for 7.4 volt operation. Use up to ~3-4oz models. Specifications: KV 4500 Voltage 7.4V No load current 0.5A No load RPM 33200 +/- 3% Max continuous current 2A Continuous RPM 21000+/- 3% Resistance 1.18ohm Dimensions 13 x 4.6mm Shaft Dia. 1.5mm Weight 3.5g