Gauntlets

Gauntlets are a piece of Glove-class arm equipment available in both Golden Sun and Golden Sun: The Lost Age. It is sold in armor vendors at Altin, Kalay, and Tolbi in Golden Sun and at Kibombo in The Lost Age. These gloves can be equipped on all Adepts in both games. It increases the equipped Adept's base Defense rating by 23 points. Its buy value is 1600 coins and its sell value is 1200 coins.

In Golden Sun, Gauntlets are a strong purchase in Altin to replace any Leather Gloves and Bronze Shields your Adepts might be equipped with, but unless you are made of money it would not be worth replacing an almost-as-strong Iron Shield with, and it might only be barely significant enough a defense upgrade over Armlets to invest in. You might also have already found the Dragon Shield in Altin Peak which is stronger than Gauntlets, so obviously you wouldn't replace that with Gauntlets.

In The Lost Age, Gauntlets are only sold in Kibombo following the events in the Gabomba Statue. Its usefulness is more limited than in the previous game because you might have already found the superior artifacts Fujin Shield and Bone Armlet, and Piers is guaranteed to be equipped an Iron Shield which is only a few defense points less than Gauntlets. It is only a safely good purchase for an Adept equipped with an Armlet or below.