Some cards offer additional authentication schemes or programmability that can be selected through this interface.
Some vendors offer other gimmicks, such as a calculator or light-sensitive inputs.
In choosing a token solution, it is important to review the actual hardware that your users will employ. Several key areas to consider are battery life, displays, interfaces, programming, size and durability. Output displays typically are LCD-based though the quality and clarity of these screens varies greatly. A token should be easy to read at a glance when next to your keyboard or monitor. Consider if the interfaces on the token are easy to work with, if programming can be accomplished quickly and accurately, and if the size of the device is conducive to easy handling while not being easy to misplace.