65a29c43_re_Sets___Performance_Products__FireCore50
[0] Inner Jacket [FireCore250] A high dielectric strength inner jacket compound is extruded over the 250ohm high energy core. This inner core helps keep the voltage "locked" into the wire. [FireCore50] 
High heat resistance, added dielectric strength and flexibility are the advantages of the custom engineered inner jacket. The inner jacket helps dissipate the heat of the high voltage Firecore50 ultra low resistance core. With the inner core helping to dissipate heat and staying flexible, the core itself retains its capacitance, voltage and flexibility properties. These properties are what make the Firecore50 ignition wire last longer and stand up to extended race use.
FAQ  :: Custom Wire Sets & Performance Products
FireCore50