Chain Mail

A Chain Mail is an Armor-class bodywear available in both Golden Sun and Golden Sun: The Lost Age. It is sold in armor vendors at Altin and Kalay in Golden Sun and at Kibombo in The Lost Age. Being an Armor-class piece of body protection, a Chain Mail can be equipped on warrior-style Adepts, namely Isaac and Garet in the first game, along with Felix and Piers in the second. It is, in fact, one of Piers' initial equipment when he joins Felix's party. It increases the equipped Adept's base Defense rating by 25 points. Its buy value is 2000 coins and its sell value is 1500 coins.

In Golden Sun when Chain Mail can first be bought in Altin, it is not often a good thing to buy because it is likely your party has already found some armor artifacts, like the Psynergy Armor in Mercury Lighthouse and the Elven Shirt in Mogall Forest, whose additional effects more than make up for the fact they each have just a few Defense points less than a Chain Mail.

In Golden Sun: The Lost Age, Chain Mail can first be bought in Kibombo after the Gabomba Statue dungeon and related events, and you most likely would never buy one because Piers joins your party shortly beforehand already equipped with a Chain Mail, and Felix is probably equipped with a Psynergy Armor bought much earlier at Mikasalla. A Psynergy Armor, quite frankly, is better than a Chain Mail even though its monetary value is literally half as much and it has a few less defense points, because it has a significant PP-meter boost that is very useful at that point in the game. It is possible Felix will have found the Ixion Mail in Alhafra before going to Kibombo, too, and if he has a spare unequipped Psynergy Armor in his inventory when he meets Piers it would be sound to replace Piers' Chain Mail with that armor as soon as the latter joins.