These are a set of 6 stainless steel rocker box studs, nuts and washers. They are the small studs that go at the front of the rocker box's and hang down through the head at the front and rear. Triumph part number was E2980 and also E1540 They will fit all of the Triumph range including the iron head rigid models, with the exception of the unit construction 350 and 500's. The thread is cycle one end whitworth the other.
E2980-set - W1-12