Taylor 409 Pro Race 10.4mm Under Headers style high performance ignition wires are designed for street and track performance. Featuring tightly woven heat treated fiberglass braid over a 100% silicone Spiro-Pro ignition wire providing a 3-layer jacke t these wires have a 102000 volt dielectric strength and thermal protection to 600 degrees.The spiral wound core with 350 ohm resistance per foot has excellent EMI and RFI suppression making them perfect for extreme electronic ignition systems . Each set includes color coordinated low profile 100% silicone PRO BOOTS featuring vibration proof double spring locking spark plug terminals.Made in U SAApplications:Chevrolet small block engines with HEI.Installation Notes:Set will require cutting to fit terminating and booting the distributor end