This is a spececual philatelic gem of H.K 1953 QEII Coronation private cover affixed 10c x 5 pcs QE Coronation, cancelled 2 HONG KONG double ring 1 & 4 which are cancelled with two different double-ring "HONG KONG" postmarks (identified as types 1 and 4). 
This type of FDC is sought after by collectors of Hong Kong philately and Queen Elizabeth II coronation issues.