Champion's Helm is a rare Artifact — Equipment card from Commander Masters (CMM), collector number 654. Current market price: $6.35 (foil $6.16), TCGplayer market prices via Scryfall.
Equipped creature gets +2/+2. As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.) Equip {1}