The Reality Chip is a rare Legendary Artifact Creature — Equipment Jellyfish card from Kamigawa: Neon Dynasty Promos (PNEO), collector number 74p. Current market price: $4.18 (foil $4.97), TCGplayer market prices via Scryfall.
You may look at the top card of your library any time. As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library. Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)