Exertools Gymballs in 3 sizes
The 300lb Burst Resistant Gymballs (also called Swiss or Fitness Balls) are used for core, balance and strength training. If you haven't tried Gymballs before, now is a great time with special savings. Make sure to order the P10 Personal Hand Pump if you don't already own a pump and needle to pump up your gym ball.
Already using a Gym Ball? Consider the Ball Jacket, or stability base shown below.