This would Be great for a Rdm or Blm around 50 that is Taru, Mithra, or Hume. Elvaan & Galka (Elvaan Rule) need mp rings in the worst way and 5 mp does not sufice for the ginormous mp penalty for being Elvaan. On the other hand you could just have a serket ring and on of these that would be a good combo.
I'm a level 70 Elvaan Black Mage and I only buy +INT gear. I would have taken one of these rings in a heart beat at level 50 had I known about them then. As stated above, I only buy INT gear, but if any of that INT gear had a tad bit of MP in it as well, I wasn't complaining. ^_~ Just an FYI about Elvaan Black Mages for ya. One.