These Pro Mag replacement cap and rotor kits are injection-molded from Dupont Rynite material for high voltage insulation characteristics with heavy-duty construction. Inside the cap, there are thick vanes to help agitate the air to prevent the chance of crossfire. Stainless terminals are used for resistance to corrosion, caused by ozone in the cap. The rotor is also molded out of Rynite and features a brass/stainless steel rotor tip, plus a lock screw for secure mounting to the shaft.