Spark Plug/Spark Plug Adaptor Folded Washer - 18mm. Large 4 Way Turreted Top 18mm Spark Plug Holder - Polished Aluminium. Large 4 Way Turreted Top 14mm Spark Plug Holder - Polished Aluminium. When fitted 1/2" reach spark plugs need to be fitted for electrodes to reach combustion chamber.
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