RAF operations room plaque - 'RAR'

Unusual 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/code allocated to a specific enemy raid.  Approximately 7.4 x 3.8cm (3 x 1.5").  The clear acetate has been coloured black on the reverse and has the lettering 'RAR' marked in white on the front.  Came in with other similar plaques and operations room pieces.  A fantastic opportunity to create a small operations room display.  Quite good condition.  Stock code M25993.

NB. Map not included.