Read from the World of Warcraft client build files.
How Sightfinder Helm Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Sightfinder Helm suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Sightfinder Helm is part of the transmog set Swarmbreaker's Battleplate (Warrior, Paladin and Death Knight only). The other 16 pieces:
Built from the World of Warcraft client build files and recorded Auction House snapshots.
Where Sightfinder Helm Fits
Other Items Named Sightfinder Helm
2 other items in the current build are also called Sightfinder Helm. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 81274 (81269 to 81280) were usually added in the same batch as Sightfinder Helm: the same quest line, zone, vendor or reward set.