ACDelco 16 Professional RAPIDFIRE Spark Plug (Pack of 1) Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures Pure copper core provides great heat transfer and helps maximize plug durability Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system Ribless insulator helps optimize plug to boot seal