This coupler has a smooth, good-looking, corrosion-resistant zinc-plated finish. It is sized for tongue stock with a 2" width (tongue height is not critical as long as it's 2" or more). The cup is sized for a 1 7/8" ball.
Mounting holes on this coupler are sized at 2 1/4" center-to-center. If you're looking to match this up with a swivel, this would work with the Shelby swivel.