This is a new Cylinder Head Stud Insert (also commonly called a "Case Saver") for air-cooled Volkswagen engines with 12mm studs. These are used during engine rebuilds to repair or reinforce damaged threads in the engine case where the cylinder head studs are installed. A full VW engine case typically requires 16 inserts. These are sold as each.
Product Specifications
Function: Repairs pulled head stud threads by providing a larger, more secure outer diameter while retaining the standard inner thread for the stud.
Dimensions:
Inner Diameter (ID): M8 x 1.25 (Standard for most 8mm head studs).