Walker Products 900-P2041 Thundercore Ultra Spark Plug Coil Boot is precision manufactured from premium components in an ISO 9001-2008/TS16949 certified facility. The boot is designed to provide outstanding performance and is manufactured to meet and exceed all Original Equipment Manufacturer (OEM) specifications and test requirements. The boots feature stainless steel springs with resistors that are engineered to suppress RFI. It is engineered to deliver the maximum voltage to the spark plug while providing weatherproof seals that minimize moisture accumulation. Package includes dielectric grease. Walker Products specializes in the engineering, manufacturing, and distribution of automotive engine management components. Walker is committed to meeting or exceeding the Original Equipment Manufacturer (OEM) or equivalent standards and specifications. This effort is backed by Walkers own manufacturing, product management and engineering expertise.