NGK metal glow plugs are trusted by OEM diesel engine manufacturers around the world to perform under the harshest conditions. NGK metal glow plugs are equipped with a heating coil in a glow rod made of heat-resistant magnesium oxide between the heating and regulating coils. Magnesium oxide is an outstanding thermal conductor (quickly dissipating heat), while protecting the heating coils from vibration and shock. NGK metal glow plugs feature excellent gas-tight sealing qualities that deliver superior electrical insulation and protection against combustion gas. NGKs metal composition helps reduce carbon accumulation to prevent short circuits, while the unique shell design provides excellent heat transfer.