This Schwerman Ball Chair puts a spin on fun and spunky seating. Designed with an anti-burst plastic exercise ball, when fully inflated height lowers slightly when occupied. This Ball chair allows a little zip in your sit by providing movement that not only helps you sit comfortably but also helps you concentrate and supports better posture and balance. Movement keeps your mind open, while keeping your body actively engaged, no matter if you're problem-solving or having a casual conversation. This Swivel has a rubber molded base so the chair doesn't slip.