Dimir Locket is a common Artifact card from Guilds of Ravnica (GRN), collector number 234. Current market price: $0.17 (foil $0.48), TCGplayer market prices via Scryfall.
{T}: Add {U} or {B}. {U/B}{U/B}{U/B}{U/B}, {T}, Sacrifice this artifact: Draw two cards.