Mizium Apparatus

Requires attunement
While wearing this 8 lb. arcane focus, you can
attempt to cast a spell that you don't know or
have prepared. The spell you choose must be
on your class's spell list and of a level for which
you have a spell slot, and you must provide the
spell's components. You expend a spell slot to
cast the spell as normal, but before resolving it
you must make an Arcana check. The DC is 10+
twice the level of the spell slot you expend to
cast the spell.