Arcanite Fishing Pole

Arcanite Fishing Pole is the best fishing pole available for fishing, with a +40 bonus to fishing skill.



Source
This item is a competitive reward from the quest, the prize turn-in for the Stranglethorn Fishing Extravaganza.

The Arcanite Fishing Pole has no explicit level requirement, however one must be level 10 to train in Artisan level fishing in order to reach fishing skill level 300 and equip the Arcanite Fishing Rod. You can acquire it earlier, but not equip it.

Cataclysm
According to El's Extreme Anglin', the Arcanite Fishing Pole was to meant to recieve a new icon and model in Cataclysm. However, Blizzard only changed it model in Patch 4.0.3.