Yes, it is in fact an inexpensive brass finger ring that has been crushed or flattened. While this example carries a military style motif, the ring is not military in origin. These adjustable finger rings appear to have been popular around the mid-20th Century, give or take a couple decades. The inexpensive manufacture and "one size fits all" lends for distribution through "Nickle & Dime" stores, vending machines, or free prize "give-aways" inside other products.
CC Hunter