Quote Originally Posted by Anzaman View Post
"When completing a level 51 to 59 dungeon or a level 61 to 69 dungeon, players will always receive one piece of gear equippable by their current class or job."
"*Players will not receive gear that is already in their inventory."

http://eu.finalfantasyxiv.com/lodest...e7c51abfa95055
That, however sometimes you get dropped an accessory, hence a lot of people do not realized that they have gotten a "free" piece of gear. Also if you have a piece of gear already, that's from these dungeons, you will receive an red error message, indicating that the system at least tried of giving you a free gear piece lol.