Experiences Many of the Same Advantages of a fitness center Ball While Performing Lower Back & Abdominal ExerciseFeatures Can withstand up to 350 lbs. Promotes core stabilityTextured surface improves hold Can become use in more chairs too Support and challenge the spinal muscles while boosting position For children with hyperactive stressed systems enhances calmness and concentrationCan be used on the flooring for exercises to Improve stability Increase strength The j fit Fit Disc is a wonderful device that promotes core stability and can feel used to strengthen the back and abdominal muscles. The fit disc can feel used on the ground in conjunction with numerous exercises including crunches, drive ups, lunges and squats to improve stability and strengthen stabilizer muscles. This item can additionally be used in most standard chairs as well as the seats of your vehicle to help and strengthen the spine and promote much better posture. Inflatable with a standard ball needle and pump. j fit, inc.