Posture Pump® Elliptical Back Rocker™ Model 2000 Relieves back stiffness and discomfort Dual inflation mechanism gradually lifts, stretches and separates the joints 2 uniquely angled air cells create multi-vectored force and promote disc & joint lubrication Built-in Rocking Mechanism allows you to excercise your abdominal muscles while shaping & stretching the lower back . Prices do not include a fee for evaluation and training by a health care professional. The manufacturer highly recommends that you contact a health care professional and receive personal evaluation and training on the use of all Posture Pump® products. In all cases, a health care professional should be consulted before beginning any exercise program.