Ring of arcane might
(Magic Item Compendium, page 121)
Price (Item Level): 20,000 gp (15th)
Body Slot: Ring
Caster Level: 8th
Aura: Moderate; (DC 19) no school
Activation: —
Weight: —
This bronze ring is forged in the shape of a serpent devouring its own tail.
While wearing a ring of arcane might, you gain a +1 bonus to your arcane caster level for the purpose of spell penetration checks, caster level checks, and all level-based variables of any arcane spells you cast.
Prerequisites: Forge Ring, limited wish.
Cost to Create: 10,000 gp, 800 XP, 20 days.