This hoverboard doesn't have any unlockable upgrades.
Sleigh is a hoverboard in Subway Surfers. Like any other hoverboard, it protects you from crashing for 30 seconds. When crashed, it will explode and need a few seconds to recharge. It has no special ability. It has the appearance of a decorated blue and cyan sleigh. Like most of others limited hoverboards, it costs 50,000.