BOSU Ballast Ball PRO stays put, so that balls don't wander around the gym floor. of high-quality, burst-resistant material, it has a six-sided design for proper alignment and positioning. the BOSU Ballast Ball, individuals can perform exercise progressions and dynamic drills that aren't possible on a regular stability ball. product is translucent light blue with white multi-dimensional material, and includes a foot pump and workout DVD. can be inflated between 55cm and 65 cm, 6.5 lbs. in the USA.