This is a vintage Zippo style lighter. It is in used, fair condition. The brushed nickel plating is worn and the lid hinge is rusty (pictured). Nonetheless, the lighter's working parts still move although I have not tested its function as a lighter.
The military emblem is a bit of a mystery to me. It resembles both the U.S. Army's 3rd Corps and the 3rd U.S. Marine Division insignia. The blue background aligns more closely with the 3rd Corps, but the emblem on the lighter is different than the actual patch.
The lighter is simply labeled "Japan". There were a number of Japanese companies that made knock-off Zippos and they were very popular as PX purchase items and gifts during the Cold War.