Crystal Bangle is a mid-ranked armor that provides 70 Defense, 8 Def%, 45 Magic Defense, 1% MDef%, and three linked materia slots with normal growth. It can be bought for 4,800 gil at Mideel or won at the Gold Saucer.
Crystal Bangle is an accessory that provides Max HP +100%, and one can be used to increase a creature's Max HP. It can be found at Youth League Headquarters (Chapter 5), dropped from Machina Panzer, Aranea (Oversoul), or Ultima Weapon (Oversoul), bribed from Balivarha (35,032 gil) or Earth Worm (Oversoul; 210,200 gil) or as a random prize for winning the Aeon Cup.
Crystal Bangle is a level 64 bangle that provides +45 Defense, +220 HP, and is 1/3rd of the "Blessed Crystal" set. It can be obtained from the shop by trading 20,160 gil, Precious Watch, Crystal, and Opal x3.
Crystal Bangle is a level 30 bangle that provides +31 Defense, +340 HP, and is 1/3rd of the "Blessed Crystal" set. It can be obtained from the shop by trading 47,100 gil, Hyper Wrist, Crystal, and Girl's Desire.