Split Screen is a rare Artifact card from Unstable (UST), collector number 158. Current market price: $0.33 (foil $8.17), TCGplayer market prices via Scryfall.
When this artifact enters, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it. Play with your libraries' top cards revealed. When this artifact leaves the battlefield, shuffle your libraries together.