Switzerland. (Singapore - Thailand - China). 1940. Air Mail Registered and Charged envelope addressed to Canton, China bearing Switzerland Yvert 309, 60c brown and Air Mail Yvert 12, 1f violet tied by Zurich 2/ Fraumunster/ Briefannahme double ring '9th Sept 40' with matching registration label and hand-struck 'Charge' with Geneve/ 5gr K.L.M.' on face, routed over the Pacific with Singapore circular 'D' and '19' censor hand-stamp, carried K.L.M. to Bangkok '30th Nov' on reverse then 'C.N.A.C.' via Rangoon to Canton with vernacular receiver on reverse and hand-stamped 'Dec 4 - 1940' 0n face.
Lovely Swiss cover Charged and Registered carried over the 2 Oceans via Singapore and Thailand with Bangkok transit rarely seen on transit mail.