Ring of Magic
A band of gold with a red ruby said to store magic
The wearer of this ring is granted an additional spell slot of the caster’s highest level spell. Effectively this grants the wearer 1 more spell per day of any level. (5e)
This solid gold ring features a small red ruby brimming with magic power. There have been many attempts to make “limitless casting” items, rings such as these are such an attempt. This particular ring has passed through the hands of many spellcasters and its maker is unknown.