What is medal with oak leaf cluster?

A medal with oak leaf cluster is a military award given to members of the armed forces for heroic or meritorious service. The oak leaf cluster is a small device that is worn on the ribbon of the medal to indicate additional awards of the same medal. For example, if a service member received a Medal of Honor and then received the medal again for another act of bravery, they would wear a Medal of Honor with an oak leaf cluster on the ribbon. The oak leaf cluster is considered a citation device and is also used on other decorations and medals. It is usually made of bronze and can be worn on both military uniforms and civilian attire.