BCrane Cams FireWire Spark Plug Wire 8-5003 ReviewbP PP Crane Cams FireWire Spark Plug Wire 8-5003 PThe ultimate 8.5mm spark plug wires for all-out racing or serious street performance.PPure silicone, double jacketed, reactive core specifically engineered for high output competition ignition systems.PUnique Reactive Core goes beyond suppression and actually filters out radio frequency interference (RFI) and electromagnetic interference (EMI).PLarge 8.5mm size with double silicone layer for protection from extreme temperatures.