Draper-Expert-51766-14-18mm-Spark-Plug-Chaser-Draper-Expert-51766-Expert-Quality-covering-two-common-sizes-14mm-&-18mm-spark-plugs-threads-Driven-by-a-21mm-spark-plug-socket-will-clean-carbon-&-corrosion-clogged-spark-plug-threads-Can-also-be-used-to-repair-minor-thread-damage-Display-packed-br-Draper-Expert-51766-14-18mm-Spark-Plug-Chaser