Thanks for Shopping in our Amazon Store, we are a professional business company, we YUEWO always providing the best products and the best service ! When you use yoga, you can combine yoga flexibility and muscle endurance with the strength and muscle conditioning of resistance exercises. Size:79*52cm Material: PVC Composition: special chair +55cm diameter explosion-proof yoga ball + foot pump Color: Black Size: 79*52cm (31.1*20.5inch) Ryukyu weight bearing: 150KGS Shuttle ball size: 55cm Is it assembled: yes Products: Yoga Studio, Bedroom, Balcony, Office, Gym, Outdoor Includes: 1* removable exercise ball 1*an air pump 1*an adjustable metal support bar, 4 *easy-glide casters and 1* a desktop exercise guide Yoga Ball size: usually diameter 65cm suit for 160-165cm height,diameter 55cm suit for 150-160cm height ★ Tips: 1.Yoga chair Auxiliary chair Fitness inverted chair Home yoga auxiliary stool Multifunctional yoga chair Yoga ball chair corrects bad sitting posture, exercises the core muscle group on your torso, reduces the meridians caused by poor sitting posture, and can relieve the soreness of the waist after correcting the bad sitting posture. 2.It may be necessary to re-inflate the ball after initial inflation, allowing the ball’s material to stretch to its final size. Inflate ball with air, let stand for 24 hours, deflate 50% then fill again to 55cm height. √ Due to different measurement tools and measurement methods, there may be an error of 1-3cm! √ Due to different lighting, there may be color, but please choose carefully within a reasonable range! √ If you have any questions, please feel free to contact us!