Proximity readers are opening or closing devices that use a contactless technology to communicate with the proximity card. The read range of a proximity reader is the distance from the reader face to the card that is required to establish a wireless connection. Read ranges can be anywhere from 2 inches to tens of feet. Proximity readers are typically not stand alone devices (but proximity readers can be integrated into access controllers). That means proximity readers require a access controller to make the decision on whether or not the card is valid.