Amber Prison is a rare Artifact card from Mirage (MIR), collector number 292. Current market price: $0.46, TCGplayer market prices via Scryfall.
You may choose not to untap this artifact during your untap step. {4}, {T}: Tap target artifact, creature, or land. That permanent doesn't untap during its controller's untap step for as long as this artifact remains tapped.