What is one feature of the key card?

One feature of the key card is that it can register balance protection. This feature is significant because it offers users the ability to safeguard their funds in the event that the card is lost or stolen. When balance protection is registered, the cardholder can recover any remaining stored value on the card, which enhances the security and reliability of using the key card for transit purposes.

The other options provided do not align with the characteristics typically associated with key cards. For instance, they may imply restrictions or fees that are generally not applicable, making balance protection a valuable aspect of the key card's functionality. This feature promotes user confidence in utilizing the card for seamless travel within the transit system.