Zenergy Swivel Ball Chair, Black Seat/Black Back, Black Base. Playful in form and design, this upholstered exercise ball chair invites active seating and may help support enhanced focus and performance. The chair features 360-degree swivel functionality to allow users to access their entire workspace and create continuous movement. The 17 1/2" anti-burst ball may help improve posture and balance by responding to user-controlled movement. Ideal for office and classroom use, the chair can also be in homes offices, break rooms or gathering areas. The chair also features an anti-skid base for stability on all floor types. Air pump included. Designed by Thomas Walser. Recommended Applications: Guest, Reception, Waiting Room & Lounge; Seat Color: Black; Back Color: Black; Color Family: Black.