The King's Badge For War Service:

The King's Badge For War Service was the World War Two equivalent of the Silver War Badge issued in the First World War. It was initially issued to servicemen that had been discharged as no longer fit for service due to age or injury.

It was later issued to members of the Home Guard, Fire Service and civilians.

There appears to have been two versions, one with a 2.5cm diameter and another slightly smaller at 1.8cm diameter. The badge shown is the larger 2.5cm version and part of my medal and badge collection. It was designed to be worn in a button hole and is not numbered. The badge is worth between 15 to 20.
Kings Badge for War Service