Netherlands East Indies. (Singapore). 1940. Envelope addressed to the 'American Radio Relay League, West Hartford, United States' bearing SG 399, 3c yellow-green tied by triangular Medan/ Seint via Radio date stamp '3rd May 40', endorsed 'Printed' and routed via Singapore with 'Passed For Transmission/ Singapore/ 49' censor cachet on face.
Nice item paying the printed matter Trans-Pacific rate with Sent via Radio cachet.