Available in user (blank) or supervisor (CompX logo) format. These are cleaner and more reliable than magnetic stripe cards, and provide more encryption than basic HID proximity cards. Communication between the lock and the card is accomplished via a small antennae inside the card, and inside the prox reader on the lock housing. When the card is tapped against the prox reader, access will either be granted or denied, based on whether that user's card is an enrolled credential in that eLock.