HKS Super Fire Racing Spark Plug M-XL Series - M45XL Golf This prevents the diaphragm from

This prevents the diaphragm from sealing

This version has full aluminum construction with for weight reduction and has wider than standard shaft for extra durability and impact

Included is everything required for installation to the engine and can be used throughout different tuning step up to the 300ps mark

Replaces the weaker plastic valve

that's a great upgrade for the oem plastic housing

HKS Super Fire Racing Spark Plug M-XL Series - M45XL Golf This prevents the diaphragm fromThese are XL Type and use both Iridium and Platinum for utmost performance for street and race applications. This plugs are recommended for reliable ignition, durability and anti carbon buildup under high load. This are the Ultimate spark plug for increasing performance of tuned or stock engines.