RAF Poster. 'Hercules XI Main Engine System Lubrication'. Thick paper poster, approx. 96 x 66cms. Full colour cut-away illustration of the engine. Impressive display item. Marked 'RAF - For Official Use Only'. I believe this model was used in the Beaufighter, Wellington and Stirling bombers. Overall appearance is good but there is light soiling & creasing plus smallish edge tears and relatively minor damage. Stock code P13863.