You are buying one (1) NORS Auveco fastener. It is a general purpose/universal moulding clip with mastic sealer and nut with a mastic sealer for Buick, Cadillac, Chevrolet, Oldsmobile, Pontiac & GMC. This clip has a 8/32 threaded stud that is 5/8" long and is for a 5/8" wide moulding. The NEW stock mastic sealer nut has a 5/8" diameter flange.
The threaded stud is adjustable (see photos) to allow for off setting the moulding.