possibly a medic button. The popular snake on the pole is taken from the biblical account of the copper serpent (see Numbers 21:7-8) and has since become a symbol of health care in its many forms.
That's an enlisted man's medical corp emblem, I believe. The attachments look like the ones we had when I was in the military in the mid sixties. They were attached to the collar.
It's an army Medical Corps collar disk. Dating it depends on the material of the piece of metal holding the pins on. If its steel/zinc it could be WWII, but if it's brass, then it would be 1951 on. Dating Metallic Insignia: Collar Disks