A gold tone or plated collar stay made by Briar and in perfect condition. It features a Greek key motif along the bar. It is in perfect condition and the clips will hold your collar tips firmly in place. It is 2.5 inches across and 1/8th inch wide.
In various circles these are called clips, bars or stays. I think of these stays as from the 19th or early 20th century but the style is more mid century.