Hong Kong. (Airmails.) 1937. Air Mail envelope addressed to United States bearing Hong Kong SG 121, 5c violet and SG 128, 50c black /emerald (pair) tied by Hong Kong / Air (K) Mail double ring with 'First Trans Pacific Flight / Hong Kong To Guam' with 'Received First Flight F.A.M. 14' on face in black routed via Hong Kong and Guam. Nice item, the first Hong Kong to San Francisco Pan America Flight routed Hong Kong, Macau,Manila,Guam,Honolulu and San Francisco.