The Carabineer Mail is a high ranked heavy armor in Final Fantasy XII that boosts the wearer's Defense by 53 (Zodiac) or 50 (original), Strength by 8, and—unusually for a heavy armor—Magick Power by 2. It is metallic for the purposes of the boss battles against Vinuskar (though usually obtained after the boss is fought) and Ultima.
In the original PlayStation 2 version, the Carabineer Mail is sold for 11,000 gil in Balfonheim Port, and is among the best purchasable helms and thus potentially endgame equipment. It is also rarely stolen from the Giruveganus.
In the updated Zodiac versions, the Carabineer Mail is sold for 9,600 gil in Balfonheim Port, and is the best heavy armor purchasable from a normal shop. It is found as a treasure in Feywood's Ice Field of Clearsight (75% chance to appear, 50% chance for gil, 50% chance the item treasure is the Carabineer Mail without the Diamond Armlet equipped) and Necrohol of Nabudis's Cloister of the Highborn (30% chance to appear, 30% chance for gil, 50% chance the item treasure is the Carabineer Mail without the Diamond Armlet equipped). It is still rarely stolen from the Giruveganus.
Carabineer Mail is a high level armor giving 53 or 50 Defense depending on version, 8 Strength and 2 Magick Power. Its great stats make it a contender for endgame equipment, and it is the best armor the player can buy in the Zodiac versions, any upgrades being only available via sidequests and the bazaar. The strength bonuses make heavy armor ideal for frontline fighters, and the Carabineer Mail is a good armor to equip over any inferior equipment the player may have on anyone who attacks physically, although a gun-wielder does not benefit from the strength-boost. The small Magick boost it yields could be good for a katana-user, as though mystic armor offer more Magick Power, a katana-user still benefits more from Strength, and the Carabineer Mail increases both stats. In the Zodiac versions, however, the Bushi board can only unlock the Carabineer Mail with an endgame Esper.
In the Zodiac versions, Uhlan, Knight, Time Battlemage, and Foebreaker can equip it natively, and the Red Battlemage can learn it if they unlock Exodus, the Black Mage can learn it if they unlock Zeromus, and the Bushi can learn if they unlock Zodiark on their License Board. This is more worthwhile for the Red Battlemage, as Exodus opens Heavy Armor 8–10, whereas for the Black Mage, it only unlocks Heavy Armor 9, and though Bushi also gains many licenses with Zodiark, Zodiark is likely the last Esper the player gains, and so there is not much game left by this point. Carabineer Mail is only useful to buy or look for if the player has chosen these License Boards for the party.
In The Zodiac Age versions, after fighting Belias the player can choose two License Boards per party member and so more characters can benefit from heavy armor, as it is usually a good idea to match jobs that use different types of armor to bolster light armor jobs' strength, and to give more durability to spellcasters.
In The Zodiac Age versions, Carabineer Mail can potentially be procured much earlier than it is available from the shops from the Necrohol of Nabudis treasure. If the player were to get it early, they can skip purchasing many heavy armor pieces available from shops. The party can venture into the Necrohol of Nabudis after the events at the Tomb of Raithwall, but by this point, the enemies in the optional dungeon will be very tough to face.