This card is invaluable to you while you are in Hong Kong. You use it for almost everything. You use it for the double decker buses, minibuses, subway mtr, and other assortments. There are even some machines in malls and centers where you can get discounts just by scanning this card. And yes, you can scan this card anywhere, everywhere. That’s why’ll you see people putting their bags over the scanners at the subway station.