Helm of Chatzuk is a rare Artifact card from Unlimited Edition (2ED), collector number 247. Current market price: $13.86, TCGplayer market prices via Scryfall.
{1}, {T}: Target creature gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)