Upgrade Radar System option for Mobile Anti-Air is grayed out--no info

All other options in the loadout menu for the Mobile Anti-Air either are full color or have a lock on them. All of them give a description above left with what level needs to achieve, in addition to other information about the option.  The box with "Upgrade Radar System" does none of that. 

I'm using PC and there are no other issues like that in any of the other options for vehicles.