To go with the huge power of the Pro Mag 44, MSD developed a huge cap and rotor, the pro-cap. The cap has a big 5 In. terminal-to-terminal diameter, which ensures spark delivery and prevents the chance of spark scatter occurring inside the cap. The entire assembly is injection molded from DuPont Rynite material for incredible strength and high dielectric properties. The rotor features a deep skirt and thick vanes to create turbulence inside the cap. Even the rotor screws are over molded with Rynite for increased spark isolation. The top of the pro-cap is crowned with a screw-down retainer to keep all plug wires firmly attached to each terminal. The pro-cap is supplied with everything you need to convert your Pro Mag 44 or band clamp mount 12 amp generator including an aluminum base, spacer, rotor, cap, retainer and hardware.