Amulet of Contingency

Arcane focus granting +1 bonus to spell attack rolls and +1 to spell save DC
An hourglass is cut into the emerald set on the front of this silver amulet. The tiny grains of green sand within appear different every time you look, though you never see them move.
During a long rest you may conduct and store the effect of a ritual you know in the amulet.
As a bonus action you can instantly unleash the stored ritual effect.

Notes: Bonus: Spell Attacks, Bonus: Spell Save DC, Arcane focus granting +1 bonus to spell attack rolls and +1 to spell save DC