This hoverboard doesn't have any unlockable upgrades.
Jouster is a limited hoverboard, exclusive to Subway Surfers World Tour: Prague. It is the thirty-sixth limited hoverboard in Subway Surfers. Like any other hoverboard, it protects you from crashing for 30 seconds. When crashed, the hoverboard will explode and will need to recharge for a few seconds before being used again. It resembles a horse sprinting for a battle. Like most of others limited hoverboards, it costs 50,000.