Pennon Blade is a uncommon Artifact — Equipment card from Rise of the Eldrazi (ROE), collector number 221. Current market price: $0.24 (foil $0.54), TCGplayer market prices via Scryfall.
Equipped creature gets +1/+1 for each creature you control. Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)