How do I add a save bonus to a specific thing

[Shroud]

I am trying to add a +2 Item Bonus to Saves against "Illusion". How do I add that, the only options I can find would add the bonus to an entire save type (Fort/Ref/Will) instead of against a specific trait. I don't really care how I end up having to add the bonus, Item, Circumstance, etc..., but I need to find a way to have it show up when I print the character sheet.