* The Bintiva exercise ball is crafted from professional grade, anti-burst, Phthalate free, green, materials. * Textured material ensures safety when being used as a birthing ball, or ball chair * Swiss ball promotes core stability, strengthens muscle tone, improves balance and body posture. * Stability ball provides ergonomic seating, relieves back pain and shoulder aches. * Gym ball set includes convenient foot and fitness ball user's guide. * Sizing Suggestions 5'0" - 5'6" -- 55cm / 22" ball 5'7" - 6'1" -- 65cm / 26" ball 6'2" - 6'7" -- 75cm / 30" ball Please note: The above guidelines are merely suggestions, many factors such as of your legs or torso can alter your individual size. Consult with your yoga instructor, therapist, or midwife to determine the size that is best for you. Exercise Ball Uses The stability ball is one of the most versatile pieces of fitness and is used by physical and occupational therapists; yoga and Pilates instructors; chiropractors, and other health and fitness professionals, for exercising, strengthening, rehabilitating, specific sports training, and more. It is also used as a replacement to the traditional office chair, as the simple act of sitting on the disc activates core abdominal and trunk muscles, strengthening and toning them throughout the day.