This typographed stamp, issued on January 1, 1917, was part of the British Postal Agency in China and originates from the Hong Kong King George V series overprinted "CHINA" for use at treaty ports such as Shanghai, Amoy, and Tientsin. Featuring a side portrait of King George V, it is printed in black on blue-green paper with an olive reverse and carries the watermark "Multiple Crown CA." Produced by De La Rue & Co., this 50-cent denomination was commonly used for heavier letters and parcel rates. The vertical overprint denotes its use specifically within the Chinese treaty port system under British control. It is perforated 14 and printed via typography, with clean centering and fresh original gum. This mint never hinged example is classified under Michel GB-CN 11x, Scott GB-CN 11b, Yvert GB-CN 44, and Stanley Gibbons GB-CN 12. Estimate "$90 – 110".