Sleep Ring

A Sleep Ring is a Ring-class piece of equipment found in Golden Sun and Golden Sun: The Lost Age.

Basic Description
In both games, it can be won as a prize at the Lucky Wheels minigame that uses Game Tickets and is found and played at Tolbi in the first game and at Contigo in the second. They can be bought for 1400 coins and sold for 1050 coins apiece. If broken, one can be sold for 700 or repaired for 350.

A Sleep Ring does not provide any statistics boosts while equipped. Rather, it can be Used as an item in battle (it does not need to be equipped to be used in this manner) to emulate the Sleep Psynergy, which attempts to inflict up to 3 enemies with the Sleep status condition.

Analysis
A Sleep Ring can be placed in the inventory of a party member that does not have the Sleep Psynergy so that the character has access to that specific effect as well. However, it's entirely up to the player whether they consider trying to inflict the Sleep status condition onto multiple enemies valuable, as opposed to simply defeating them with normal combat routines.