Precision-machined screw cap for automotive critical components, with an external thread and two threaded holes in its face. The cap has a silver satin finish, wrench flats between the thread and the head, and small notches on the rim. Its recessed face carries a raised boss with two tapped holes of different sizes. It is listed under critical components, a group that also covers air fork products, suspension components and pistons. Materials worked: aluminium, brass, SS, MS and plastic.