It allows Jack to Equip. the Elemental Rings, to do different typed attacks.

Phazer Zapp + Fire Ring = Red Sparks, Fire Attribute Attack, shows Flame explosion spell effect.
Phazer Zapp + Aqua Ring = Light Blue Sparks, Aqua Attribute Attack, Shows the Freeze Spell effect.
Phazer Zapp + Geo Ring = Yellow Sparks, Geo Attribute Attack.
Phazer Zapp + Wind Ring = Green Sparks, Wind Attribute Attack, Shows Vortex Spell effect.
Phazer Zapp + Thunder Ring = Violet Sparks, Thunder Attribute Attack, Shows Spark Spell effect.
Phazer Zapp + Holy Ring = White Sparks, Light Attribute Attack, Explosion clouds are completely white.
Phazer Zapp + Demon Ring = Black Sparks, Dark Attribute Attack, Explosion clouds are completely black.
Phazer Zapp + No Ring = Golden Sparks, no special effect.