Spark Plug Copper-glass seal bonds insulator, terminal post center electrove together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
Multi-rib insulator reduces dange of "flash-over"
One-piece terminal post adds strength
Resistor reduces radio frequency interference (RFI) and electrode erosion
Cold-formed steel shell precision rolled threads
Full copper core electrode provides better performance in all conditions