The ProMAXX Tool Cylinder Head Repair Kit allows technicians to rescue a botched repair where an attempt to drill out a broken exhaust manifold bolt has penetrated the cylinder head. The kit comes packaged in a convenient case with a precision drill bit, tap, locking fluid, Blind ProSert, and insert tool. The Blind ProSert fits into any 8mm bolt hole, used by most automotive manufacturers, including Ford, BMW, GM, Mercedes-Benz, CDJR, Audi, and many others. The Blind ProSert is hardened steel and black-oxide coated for corrosion resistance. The kit is made in the U.S.