Seat and arm guides work just like rail guides except they are for detachable and swing away armrests. It's hard to fold your chair when these are broken.
Seat and Arm Guides
If you have swing away or detachable armrests you will need seat and arm guides. They work just like seat rail guides as they help fold and unfold the chair. If they get broken or even worn down, they need to be replaced immediately or there is a possibility of them braking and possibly causing an injury due to a fall.