Oz Kit

An Oz kit is an oxygen tank which allows the character to breath in space. It gives the character the ability to double jump.

(Shortly after starting the game, you’re given an oxygen tank (lovingly called an Oz kit by Elpis’ Australian-sounding inhabitants). Not only does it allow you to breathe in the vacuum of space, it also controls your ability to double-jump.) http://www.gamesradar.com/borderlands-pre-sequel-review/