These are the magical implements (Genesys p. 218) used by different classes and jobs in the game.
Codex or Grimoire: used in conjunction with the arcanist's tradition. When Conjuring a companion from aether, you automatically receive the Summon Ally effect at no extra difficulty. The creature stays summoned until you dismiss it, and you need not use the concentrate maneuver to sustain it. Encumbrance 1, Price 750, Rarity 5.
Rod: used in conjunction with black magic. When using a rod to cast offensive magic, ignore the penalties imposed by the first Range modifier, and boost base damage by 4. Encumbrance 2, Price 400, Rarity 3.
Wand or Cane: used in conjunction with white magic. When using a wand or cane, Divine Only effects are one less difficulty than normal. Healing spells also restore two more wounds than normal. Encumbrance 2, Price 400, Rarity 5.