The Osaki OS-4000T is a full function massage chair that automatically detects the natural curvature of the human body and adjusts the massage to fit. The Zero Gravity position elevates the legs above the heart and more evenly distributes your weight. The OS-4000T also features hip air massage, seat vibration massage, neck and shoulder air massage, air and vibration arm massage, heat therapy for your lumbar/lower back area, and foot rollers.