The M73 is a high-voltage, heavy wattage, continuous duty capacitor. Insulation between the rotor and stator is achieved through ¼" thick mil spec ceramics riveted to the end plates. The rotor rides on ball bearings housed between the front end plate and the stainless steel shaft, and the blades are .032" thick aluminum.

Several options are available, including nine standard air gaps. The shaft's length can vary, and it can be insulated, slotted, or flatted; mounting holes can be tapped 6-32. There are several double-stator configurations available: In some, the two sections are adjacent to one another, and their capacitances increase together, enabling the user to eliminate the sliding electrical contact from the current path. In others, the two banks of stator blades lie opposite each other, and the capacitance in one section increases as the capacitance in the other decreases.