These require some explaining.  It is a set of six 3D cards, all different.  They are printed on exceptionally heavy stock.   What you see in the photo is one card, and one sample reverse:  each card has pre-printed postage, “maximum card style” yet not maximum cards.  Two sets have the postmark you see in the scan (Grades: 1, US$29).  Two sets have a different “GPO” postmark (Grades: 1, US$29).  Two sets have no postmark (Grades: 1, US$25).  We should tell you, these sold out within a few minutes of issue at all of the different Hongkong Post philatelic units.  They are extraordinary, and well worth the price.  Unusually we are putting a limit of one set per customer, and there will be a small postage surcharge due to the weight.