This hoverboard doesn't have any unlockable upgrades.
Outback is the fifth limited hoverboard in Subway Surfers, exclusive to Subway Surfers World Tour: Sydney. Like any other hoverboard, it protects you from crashing for 30 seconds. When crashed, the hoverboard will explode and need to recharge for a few seconds before using again. It has a picture of red and brown swirls with white dots on it which represents aboriginal art. Just like any other limited hoverboard, Outback costs 50,000.