Gauntlets is an accessory in Final Fantasy XII that has a different effect between the original and the Zodiac versions. In the original, they allow the wearer to block more often with their equipped shield, by increasing evasion and magick evasion by 10, except when the equipped shield has 0 in either.
In the Zodiac versions, the Gauntlets have the wearer take half physical damage when they are in HP Critical, which is the same effect as the Last Stand augment, and also give +1 to Defense and +5 to Vitality.
In the original PlayStation 2 versions, the Gauntlets can be bought for 1200 gil from Dalmasca Estersand, Dalmasca Westersand (after the Leviathan), and the Dreadnought Leviathan. They are found in a treasure in Ogir-Yensa Sandsea's Platform 1 - South Tanks (on the third oil rig when counting from the east; 70% chance to appear, 20% chance for gil, 50% chance the item treasure is Gauntlets without the Diamond Armlet ), and obtained as a reward for the hunt for Wraith.
In the updated Zodiac versions, the Gauntlets are bought for 1200 gil in Rabanastre Clan Provisioner when the player has the Clan Centurio rank of Rear Guard. They are also found as a treasure in the Trial Mode stages 27 and 35 with the Diamond Armlet equipped. It can uncommonly be stolen form the Ripe Rampager in Trial Mode Stage 3.
The Gauntlets is still a hunt reward for Wraith.
In the original version, improving shield block is not so useful and the player is likely better off wearing a different accessory; the harder enemies have "Ignore Evasion" augment and the best weapons are two-handed.
In the Zodiac versions, the Gauntlets give the same effect as the Last Stand augment; once the character has unlocked Last Stand on their License Board, equipping the Gauntlets is redundant. The effect is for the wearer to take half physical damage when they are in HP Critical. This could be situationally useful to survive for long enough for a healer to come in to top them up, but for damage-dealers, the accessory that increases damage when in HP Critical (Steel Gorget) is more beneficial. The following jobs learn Last Stand natively: Uhlan, Machinist, Knight, Monk, Time Battlemage, Archer, Foebreaker, Bushi and Shikari. The Gauntlets could be used to give the effect to the jobs that lack Last Stand, but in The Zodiac Age the player can choose two jobs per character, and so even the other jobs can get the Last Stand augment with the correct pairing.
The Zodiac versions no longer have an accessory that increases block chance with a shield. The defense increase in low health effect was originally in the Armguard accessory, which was removed from the Zodiac versions. The closest equalavent is the Jade Collar, that lets the user parry enemy attacks.