Ball knob
Red phenolic plastic.
Equatorial groove. Tapped blind hole.
Black phenolic plastic.
Equatorial groove. Brass insert and tapped blind hole.
Equatorial groove. Self-locking nylon insert.
Equatorial groove. Smooth hole.
Threaded zinc plated steel revolving stud with hexagonal locking socket.
Zinc plated steel insert and tapped blind hole.
Tapped blind hole.
Black thermoplastic, glass fiber reinforced.