Perma-Coil Master Thread Repair Kits are designed for professionals and mechanics. The Master Thread Repair Kits contain the most popular thread sizes used in automotive and light truck applications. By using Perma-Coil Thread Repair Kits, damaged threads can be brought back to the original thread size, and made better than new. Thread wear, corrosion and galling will be virtually eliminated, and the assembly will be even stronger than the original with Perma-Coil inserts.