These are very elegant brass side mount oarlock sockets. They would be right at home on one of John Welsfords Joansa's, or any rowboat, for that matter. Not only are these premium sockets nicely finished but they come with nylon bushings.
The alloy is an engineered high class brass for increased durability and corrosion resistance. The chemical composition of this brass is close to 464 Naval Brass with the addition of aluminum and nickel.