Bulldog Gear - Soft Stackable Plyometric Jump BoxThe Bulldog Gear Stackable Plyobox removes the risk of injury, scraping of the shins or falling from height so you can commit to the movement. The set contains five boxes with varying heights: 3 6 12 18 24 While catered towards elite performance and plyometric movements, the Stackable Plyobox is a great tool for scaling exercises. For example, the multiple heights allow athletes or clients to perform box jumps on lower increments.