Guild Wars 2

I looted an Exalted Helm lining which is tagged as rare in yellow or gold border and I really have no clue what it is for? Any help?

I think I saw that item several times on the map chat. If it’s not a part of the collection then it’s just a trophy that you should sell. Does it say when you right click on it that it’s an item that belongs to a collection?

Its a collection item for revenant armor that you need to have to craft mistward armor

https://wiki.guildwars2.com/wiki/Mistward_armor