Ferro-spiral core. For street or strip use. OE-type spark plug boots. Stainless steel spark plug terminals. Complete EMI and RFI suppression. 550 degree double silicone construction. Copper and nickel alloy conductor. 150 Ohms or resistance. Product Features:Ferro-Spiral CoreFor Street/Strip UseOE-Type Spark Plug BootsStainless Steel Spark Plug TerminalsComplete EMI/RFI Suppression550 Degree Double Silicone ConstructionCopper/Nickel Alloy Conductor150 Ohms Resistance