Anti-Burst Gym Ball with Pump の説明 from J-Fit
Anti-burst ball is made of a new material that is stronger than ever, holding up to 2000 pounds. The burst resistant material allows the ball to slowly deflate if punctured, minimizing the chance of injury. Specifically target your abs, back and glutes. Strengthen and tone your entire body by working your muscles in a completely new way by giving constant resistance from every direction. Great for people of all ages, and all fitness levels. Comes with a pump and an exercise guide. Size: 18" (45cm) for individuals 4'6" to 5'0".