Reaching Ring

Reaching Ring is an enchanted ring which adds one level 5, 6 and 7 spell slot. This item appears in Baldur's Gate II: Shadows of Amn and this item will probably appear in Baldur's Gate II: Enhanced Edition. It's not known where this ring can be gained.

In-game description
"Ring of Wizardry: 'Reaching Ring' This ring is masterfully enchanted, allowing the wearer to memorize more spells than normally possible. It was originally commissioned by spellcaster Gorion's Ward, apparently at great monetary and personal cost."

Note
Imported character files from Baldur's Gate will have this ring in their inventory in Throne of Bhaal if they had Evermemory, because the code for this ring is assigned to Reaching Ring in the Shadows of Amn files.