Thailand. (Domestic Air Mail Service). 1925. Registered Air Mail envelope addressed to 'Poste Restante, Korat (Siam)' bearing Siam SG 230, 2s orange-brown, SG 231, 3s chocolate, SG 232, 5s green and SG 234, 15s carmine tied by small "aeroplane" date stamp of Roi Etch dated '2nd April 25' with hand-struck framed 'R/ Roi Etch' with 'Mit Flugpost' label and small "aeroplane" arrival of Nagor Rajasima on face. '2nd May 25'.
Carried on the weekly flight of the Royal Aeronautical Service from Roi Etch to Korat (Nagor Rajasima).