Mana Vault (2ED) from Unlimited Edition, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Mark Tedin
• Card Text:
  Tap to add 3 colorless mana to your mana pool. Mana Vault doesn’t untap normally during untap phase; to untap it, you must pay 4 mana. If Mana Vault remains tapped during upkeep it does 1 damage to you. Tapping this artifact can be played as an interrupt.