This balance ball chair features a 52cm anti-burst balance ball for superior cushion and an easy-inflation air pump is included to keep your ball inflated to your optimal comfort level. The easy-glide lockable caster wheels keep the chair in place for added safety and the base has been redesigned based on customer feedback to offer additional stability and control. A Desktop Guide is also included to help get you started, illustrating multiple stretching and strengthening exercises. Designed for user heights of 5'-5'11" with a weight capacity of 300lbs.