Made up of a 17 ½ in exercise ball covered in choice of vinyl or mesh fabric for a polished and professional look. The base swivels 360 degrees with active, user-controlled movement for a more active and healthy workday. These ball chairs make for a great alternative desk chair or for use in meeting areas, gathering spaces, collaboration areas, the home or anywhere else a chair is needed. The unique design may help to support better posture and balance. Its rubber molded base ensures that the chair keeps a steady grip and does not slip during use for a safe and steady alternative to a regular exercise ball. Pump is included. Black