The 2.4 GHz cards are a long range product that allows the user to read the card/tag at a distance of many meters depending on the power of the reader being used.
These UHF cards and tags are normally ative devices, meaning that they are self powered with an internal battery. This gives them the potential for a vey long read range so ideal for remote reading of cards in high volume, high speed areas such as traffic management. The cards can have a rechargeable battrey that can be recharged to give an even product lifetime.