A contactless smart card is a card in which the chip communicates with the card reader through an induction technology similar to that of an RFID (at data rates of 106 to 848 kbit/s). These cards require only close proximity to an antenna to complete a transaction. They are often used when transactions must be processed quickly or hands-free, such as on mass transit systems, where a smart card can be used without even removing it from a wallet.