A
proximity card or
prox card is a "contactless"
smart card which can be read without inserting it into a reader device, as required by earlier
magnetic stripe cards such as
credit cards and "contact" type smart cards. The proximity cards are part of the contactless card technologies. Held near an electronic reader for a moment they enable the identification of an encoded number. The reader usually produces a beep or other sound to indicate the card has been read. Proximity cards typically have a read range up to 50 cm (< 15 inches) which is the main difference with
contactless smartcard with 2 to 10 cm (1 to 3 inches) . The card can often be left in a wallet or purse, and read by simply holding the wallet or purse near the reader. The term "proximity card" refers to the older 125 kHz devices as distinct to the newer 13.56 MHz
contactless smartcards.