To identify people who are permitted access to the secured area, some sort of mechanism is needed to differentiate them. While there is a world of options available, by far the two most common are the card reader and keypad. The keypad is the least costly, requires no other expense (such as cards) but is the easiest to breach. It is very valuable as a supplemental device to verify ownership of a card, but on its own, it is too easy to circumvent and has no way of verifying that the person entering is the person who owns the pass code. A card reader, either magnetic stripe or proximity, is the most common and a more secure method for entry. Magnetic stripe cards are the least expensive but must be slid through a card reader, which causes some mechanical wear and tear both on the card and the reader. While proximity cards do not have the mechanical element and are considered more durable, they can cost much more than magnetic stripe cards.