Genuine Gerber chrome 90-268 escutcheon. This escutcheon has female threads on the inside near the top.

This is the genuine Gerber 90-268 threaded escutcheon. The larger side would go against the wall. The stem would then thread onto the part of the rod that comes out. Then the handle would cover the stem and the rod. This part comes in a chrome finish, to match the 2, or the 3 handle faucet it is going onto. This is a genuine Gerber Replacement part.