MTN9201 Features: -Patented lip makes sure there is no loss of compression.-Permanent fix to damaged Cylinder threads.-Replacement insert for the MTN9200 repair kit.-Replacement spark plug insert for Ford engines.-Used to repair damaged cylinder heads with blown spark plugsReplacement insert for the Ford Cylinder Repair Kit (MTN9200). Packaged 1 insert per kit, in poly bag with label. Alloy steel insert..-Replacement Spark Plug Insert For Mountain Ford Cylinder Head Spark Plug Repair Kit. Warranty: -1 yr warranty on material and workmanship.