Thread RepairThe spark plug thread repair kit is very easy to use. Use it to cut threads, thereby repairing chipped or damaged spark plug threads and repairing spark plug setups in aluminum heads. Thread repair only requires this set of tools, no other complicated tools are required. Anyone can use it without any difficult operations. Easy to UseM14*1.25 thread repair kit is suitable for spark plug repair. Just make sure the spark plug heads are aluminum and this kit will do the job. For ease of use, you can also add a thread locking agent (not included in the set). Additionally, the socket includes a metal retainer to hold the plug inside during installation and removal. Kit ContentsKit includes 12-point tapping reamer 14mm (can be used with ratchet or 3/8" wrench) and 4 blades, sizes are 3/8", 7/16", 1/2" and 3/4". tools are complete and easy to use. Premium MaterialOur spark plug thread repair kits are made of high quality chrome vanadium steel (CR-V).Anti- oxidation, anti-corrosion and durable. Compared with similar products, we have optimized the quality to withstand more pressure and not be easily damaged.