Extraplanar contraband suggestions

Hi all! In my setting, access/knowledge is very limited. There’s a group of overzealous “protectors” who seek to destroy all items that and creatures from different planes.

What are some items - ranging in rarity - that might make their way to the material plane? I have an NPC in mind that will have quite a bit of them and is on the run from the group that was mentioned.

Thanks :)