Armory of Iroas is a common Artifact — Equipment card from Commander Legends (CMR), collector number 299. Current market price: $0.31 (foil $0.26), TCGplayer market prices via Scryfall.
Whenever equipped creature attacks, put a +1/+1 counter on it. Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)