Thailand. (Domestic Air Mail Service). 1924. Air Mail envelope hand-stamped 'Via Air Mail' in violet addressed to Bangkok bearing Sioam SG 213, 3s red-brown (pair) tied by small 'aeroplane' date stamp of ROI ETCH dated '8th Nov 1924' with Bangkok arrival on reverse '12.12.24'.
Carried on the weekly flight of the Royal Aeronautical Service from Roi Et to Bangkok.