Once every few years, Hongkong Post replaces its old set of definitive (everyday) stamps with new designs.  The latest change was in March 2025.  The set of four urban scenes (including the Convention Centre and Chek Lap Kok Airport) represent four of the new stamps’ values.  We have one set of normal, unused, unstamped cards (Grade: 1, $9) and another set of maximum cards with one value per card (Grade: 1, $16).