Choice condition insignia for this unit that disbanded in 1943.
The 532nd Coast Artillery (redesignated) Anti-Aircraft (Automatic Weapons) trained at Fort Bliss, Tx, but was disbanded in 1943. Hallmarked “ROBBINS CO. Attleboro, Mass.”
Modified from pin to screw back, professionally done, either by a jeweler but more likely by manufacture.
From the Robert Borrell Artillery Collection.