Bosu Ballast Exercise Ball BOSU Ballast Ball has 2.5 pounds of shifting weight inside that engages and targets more core and stabilizer muscles during exercises and creates more intense and efficient workouts. Overall ball weight is approximately 7 pounds. The shifting weight provides visual and audible feedback when lifting, shaking and shifting the ball. The weight also prevents the ball from rolling for added safety during workouts. Constructed of thick, high-quality, burst-resistant material that features a six-sided surface design for proper alignment and positioning to get the most out of each workout. Proudly made in the USA. Maximum user weight is 300 pounds for the 65 cm ball. Package includes BOSU Ballast Ball, pump, measuring tape, owners manual and workout DVD. The included DVD shows effective and unique ways to use the Ballast Ball. For best inflation results fill to about 90% on first inflation and allow ball to sit overnight or for several hours. After allowing the ball to sit continue inflating to full size.