RAF Operations room plaque 'MILESTONE'

Unusual clear acetate 'plaque' believed to have been used in RAF Filter and Sector Operations Rooms during the Battle of Britain and beyond to display the name allocated to a specific enemy raid.  Approximately 16 x 3.8cm marked 'MILESTONE' in black.  Came in with other similar plaques and operations room pieces.  Good condition.  A fantastic opportunity to create a small operations room display.  Stock code M26661.

NB. Map not included.