Encourages Better Posture: Designed with an anti-burst exercise ball and four legs for stability and durability; Zenergy offers the posture benefits of a yoga ball without the rolling; May help with better balance and concentration Choose Your Altitude: Each Zenergy ball chair lets you select one of two heights; Install just the feet for a sitting height of 20 inches, or both the legs and the feet for a sitting height of 23 inches; Both options are included Contemporary Design: Enhance the aesthetic of your workspace with a sleek and modern ball chair available in various colors, adding a touch of style and vibrancy to your office environment; Greenguard-Certified to help create healthier indoor environments Dimensions: Overall (Leg Option): 23”H x 22.5”D x 22.5”W; Overall (Feet Only Option): 20”H x 17.5”D x 17.5”W; Weighs 15 pounds with a 250 pound maximum user weight capacity; Manual pump included No assembly required