Moonring Mirror is a rare Artifact card from Champions of Kamigawa (CHK), collector number 262. Current market price: $0.41 (foil $7.00), TCGplayer market prices via Scryfall.
Whenever you draw a card, exile the top card of your library face down. At the beginning of your upkeep, you may exile all cards from your hand face down. If you do, put all other cards you own exiled with this artifact into your hand.