Moroso Blue Max 8mm Spiral Core Plug Wire Set for FLT, FLHT, FLHR, FLTR 27216 All Moroso spark plug wires feature silicone plug boots that withstand high temperatures (up to 600), and have a silicone jacket to reduce heat and chaffing. Locking stainless steel terminals that stay connected under high vibration. Designed to meet or exceed original equipment specifications. Glass center core offers high tensile strength Mesh pull tape provides extra strength