The Parabolas are Levi's main weapon in combat, resembling a total of eight umbrella-like swords that he keeps behind his back when not in use.
Levi mainly uses these weapons to pierce his opponents in a similar manner to a rapier, however, it's true power comes from their ability to release deadly electricity to enhance their wielder's strikes.
Combined, this allows Levi to perform his most devastating attack: Levi Volta.
Later on, during the Future Arc, Levi combines his Parabolas with the Torpedine Fulmine's Lightning Flames to unleash his ultimate technique: Super Levi Volta.