The main features of external rotor motors as drive motors are high efficiency, low temperature rising, constant speed, very low noise levels and compact construction. The relatively high inertial mass of the external rotor motor guarantees constant speeds at different loads. Motors for thermostats and beverage coolers, usually closed, are equipped with a stainless steel shaft. These motors have a high efficiency and with the electronics used they can be offered in different versions. Power source: AC115V 50/60Hz AC230V 50/60Hz . Motor diameter: ?92mm, ?102mm Propeller diameter: up to 350mm. Many different models. For the details, pls contact us.