RINGS
[...]
Spell Storing, Minor: A minor ring of spell storing contains up to three levels of spells that the wearer can 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, or pay an XP cost to cast the spell, and there is no arcane spell failure chance for wearing armor (because the ring wearer need not gesture). The activation time for the ring is same as the casting time for the relevant spell, with a minimum of 1 standard action.
For a randomly generated ring, treat it as a scroll to determine what spells are stored in it. If you roll a spell that would put the ring over the three-level limit, ignore that roll; the ring has no more spells in it. (Not every newly discovered ring need be fully charged.)
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 minor ring of spell storing.
The ring magically imparts to the wearer the names of all spells currently stored within it.
Faint evocation; CL 5th; Forge Ring, imbue with spell ability; Price 18,000 gp.
Spell Storing: As the minor ring of spell storing, except it holds up to five levels of spells.
Moderate evocation; CL 9th; Forge Ring, imbue with spell ability; Price 50,000 gp.
Spell Storing, Major: As the minor ring of spell storing, except it holds up to ten levels of spells.
Strong evocation; CL 17th; Forge Ring, imbue with spell ability; Price 200,000 gp.