55cm/ 22" Exercise Ball (Red) is Premium Grade Burst Resistant to 700lbs and 1,000 weight holding capacity. Well- suited for home or studio use. 55cm size for users 5ft-5ft 6 inches in Height. Non-slip texture and is Ideal for toning & strengthening abs, thighs & improving posture. Great for ball chair use while you work your core for Active Sitting while relieving back discomfort. Includes Hand Pump, Instructional Sheet, Extra Ball Plug, Plug Remover, Free downloadable Instructional Video at www.zenathletics.com