Ring of Gix is a rare Artifact card from Urza's Legacy (ULG), collector number 131. Current market price: $0.99 (foil $69.99), TCGplayer market prices via Scryfall.
Echo {3} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.) {1}, {T}: Tap target artifact, creature, or land.