Hourglass of the Lost is a rare Artifact card from Modern Horizons 3 Commander (M3C), collector number 40. Current market price: $1.22, TCGplayer market prices via Scryfall.
{T}: Add {W}. Put a time counter on this artifact. {T}, Remove X time counters from this artifact and exile it: Return each nonland permanent card with mana value X from your graveyard to the battlefield. Activate only as a sorcery.