Also known as a yoga ball, The Natural Fitness Pro Burst Resistant Exercise Ball will help you take crunches, bridges, planks and stretches to the next level by continually engaging your core and back muscles for improved strength and balance. Build stabilizer muscles and increase flexibility by using a yoga ball. FEATURES: Burst resistant exercise ball holds up to 300 lbs Non-toxic and phthalate-free used for fitness, core stability, yoga, Pilates and balance Latex free Helps improve back and core strength Includes exercise instruction chart, a fast pump, two inflation plus and a plug remover WARRANTY: This product is backed by a 90-day manufacturer's warranty period