ACCEL's SuperStock 4000 series spark plug wire sets are designed to upgrade an OE ignition system for high-spark delivery levels for street driven applications. The 450 degree F rated silicone jacket is extruded over a tightly woven; rugged fiberglass braid. The braid is applied over high dielectric strength EPDM (Ethylene Propylene Diene Monomer) inner insulation for ignition wire performance that exceeds SAE specifications. 7mm And 8mm High Gloss Silicone Jacket 450 F Rated Silicone Jacket Stainless Steel Plug Terminals RFI Suppression For Street Driven Applications Custom-fit Universal And Import Coverage