The first version of Gear 4 revealed is (or Bounceman): Gomu Gomu no Mi/Gear 4 Techniques - One Piece Wiki

This episode is widely considered one of the most hype moments in the One Piece anime due to the dramatic animation shift and the sheer power display.

This episode marks the climax of the battle against Donquixote Doflamingo. After being overwhelmed by Doflamingo's power and his "Torikago" (Birdcage) threatening the citizens of Dressrosa, Luffy reveals the result of his two-year training on Rusukaina Island.

Luffy first activates Gear 4 in of the anime, which aired on January 17, 2016 . In the manga, this landmark event occurred in Chapter 784 , titled simply "Gear 4".