Ring of spell storing

A ring of spell storing contains up to three levels of spells, which the wearer may command the ring to cast. Each spell has a caster level equal to the minimum level needed to cast that spell. The user need not provide any material components or focus, nor pay any other cost to cast the spell, and there is no arcane spell failure chance for wearing armor (because the ring wearer need not gesture), nor does magical silence prevent the ring’s use (because the wearer need not speak). A swift (mental) action is required to cause the ring to cast a spell that is stored in it; the casting time of the spell is as normal, but the wearer can take any actions he wishes during this time, as the spellcasting is done by the ring itself. (However, the wearer cannot take the ring off while the spell is being cast without interrupting the casting. Likewise, if the wearer moves out of range of spell’s target, or otherwise takes actions that make it impossible for the spellcasting to be completed, the spell fails, and is not expended.)

A spellcaster can cast any spells into the ring, so long as the total spell levels do not add up to more than three. Metamagic versions of spells take up storage space equal to their spell level modified by the metamagic feat. A spellcaster can use a scroll to put a spell into the ring of spell storing.

The ring magically imparts to the wearer the names of all spells currently stored within it.

More powerful versions of such rings are rumored to exist, which can store more levels of spells.