It appears to be a "rally" pin of some sort...
Like "rally the boys" war thing...
it is a "up and at' em" enamel pin.
Did a slight search... nothing came up... prolly rarer
Check it it further from here yourself
The 4th Composite Group is an inactive United States Army Air Corps unit. It was last was assigned to the United States Army Philippine Department at Nichols Field, Commonwealth of the Philippines. It was disbanded on 1 November 1941.[1] The Group was the primary command and control organization for all Army Air Corps units in the Commonwealth of the Philippines from 1919 until the eve of World War II in November 1941.