Bosch 09139 Premium Spark Plug Wire Set Stainless steel Mag winding delivers maximum voltage to the spark plug for a hotter, more powerful, and longer spark resulting in optimum engine performance while reducing the chance for misfire, and eliminating radio static 100% Pure silicone jacket resists oil penetration, for lifetime protection against wire set failure EPDM inner insulation stops power-robbing voltage leaks "Snap lock" terminals or OEM style connectors ensures that wires are tightly crimped to the connectors to exceed OEM standards, providing worry-free installation and re-installation Backed by a "no hassle" lifetime guarantee