This is a variant WWI era American army captain’s rank insignia I have not come across before. The hollow backed domed bars are made with false embroidered design on the diagonal, interrupted. The two bars are held together by then strips of the same metal. The pins have the extension protruding forward at the hinge. The bars have an open clutch.
No markings, 25mm high, and have a thinner profile than most others of the period.
