Nightingale Armor

The Nightingale Armor is set of light armor given to you and Brynjolf by Karliah before performing the initiation ritual of the Nightingales during the Trinity Restored quest for the Thieves Guild. All of the armor pieces are obtained from a box with the Nightingales symbol emblazoned on it. The Nightingale Armor is the only armor other than the Dragon Priest Masks and the shrouded armor of the Dark Brotherhood to feature a cowl. Like all light armor, the armor value depends on the player's armor skill, while the enchantments depend on player level with the highest enchantments coming at level 32.

Pieces in the set
It is made up of the following pieces:

You can also obtain these matching weapons; Full video guide can be found here.
 * Nightingale Blade
 * Nightingale Bow

Trivia

 * The Nightingale armor can not be replaced if lost.

Bugs

 * If the robes are worn on a Khajiit/Argonian the tail will clip through the cape.
 * Sometimes, Nightingale armor can't be upgraded even when you have sufficient smithing skill, smithing perks and void salts. (This could possibly be a result of having the fine-cut void salts in your inventory, turning them in to captain of the ship in Dawnstar should fix the bug)
 * Sometimes the coloring of the Hood will go and it will become white (PS3 confirmed, 360 confirmed but only when equipping in shadows, others need confirmation). Reinstalling the game seems to fix this. Another way to fix this is to drop it on the ground during the day time and wait until night, pick it back up and equip it.
 * There is a bug when you try to retrieve the armor this way, when you click the stone nothing happens.
 * Argonian and Khajiit faces are shortened when wearing the hood and look like normal human head models.