Raid Designation Plaque, 1 Letter Series. Headquarters Fighter Command Reference No. T.D. 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 'H' printed in black on some form of early yellow plastic. It would have been positioned on the raid block along with other tiles representing height, strength and so on of hostile/enemy aircraft. It fits both the metal and wooden style blocks as shown but please note you are buying one single tile - the block and map 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 M23681.