Raid Designation Plaque, 1 Letter Series. Air Ministry Reference No. 4M/45. Headquarters Fighter Command Reference No. R.G. Incredibly rare 'Raid Block' plaque/tile used in RAF Filter and Sector Operations Rooms during the Battle of Britain and beyond to display important information relating an enemy raid. The raid block itself was normally positioned at the head of the plotting path and provided information such as strength, height and whether the aircraft were 'hostile', 'friendly', or 'unknown'. This plaque measures approximately 1" x 0.75" /25 x 19mm and has the letter 'F' printed in red on some form of early white plastic. It would have been positioned on the raid block along with other tiles representing height, strength and so on. It fits both the metal and wooden style blocks as shown but please note you are buying one single tile - the blocks are shown for illustrative purposes only. We have a small quantity of plaques/tiles/counters available. A fantastic opportunity to create a small Operations Room display. Stock code M23374-2X.