The M-73 is a high-voltage, heavy-wattage, continuous duty capacitor. Insulation between rotor and stator is achieved through 1/4" thick, high quality, military spec ceramics riveted to the plated steel end plates. These end plates are tied together by solid aluminum and brass bars, forming a rigid structure. The rotor rides on ball bearings housed between the front end plate and the stainless steel shaft. Blades are heavy .030" thick aluminum. Length dimension is measured from ends of mounting feet.