●THREAD REPAIR KIT: The LLNDEI 38900 spark plug thread repair kit solves the problem of cylinder head damage caused by cracked spark plugs. ●HEAVY-DUTY SPARK PLUG THREAD REPAIR KIT: The line up guides, twist drills and screw taps in this kit are manufactured from high quality thickened steel. The robust and durable construction allows you to use them for a long time. ●APPLICABLE MODELS: Spark plug thread repair kit are designed to repair Ford 1996 to 2003 model year vehicles and can be used to repair Ford 4.6L, 5.4L, and 6.8V-10 2-valve engines, all other engines are not suitable, please check before purchase. ●MASTER SET INCLUDES: 1x Screw Tap; 1x Twist Drill; 8x M14-1.25 Inserts; 4x Snap Iron Pieces; 1x Line up Guide; 1x Cylinder Leak Tester. ●CAVEAT: Before beginning repairs, use a cylinder leakage tester to check that the motors valves are closed and to remove metal shavings from the cylinders after each step. ●SERVICE GUARANTEE: All LLNDEI parts are rigorously tested, ensuring peak performance and durability. LLNDEI Tools meet or exceed ANSI and DIN performance standards. It comes with 2 Year Warranty. If you have any problem, please feel free to contact us.