This is the backrest that produces soothing sounds and acoustic vibrations to relax the mind and body. An internal transducer produces low frequency sound vibrations (20 -100 Hz) that you feel as they resonate through the backrest and into your body, relaxing tense muscles and helping to alleviate stress. Two speakers imbedded in the head of the backrest emit calming digital sounds like ocean surf, a soft acoustic guitar, and a melodius flute that were recorded live. A tethered controller allows you to select from 12 vibroacoustic programs that last three to six minutes, adjust the vibration intensity, and change the volume. The controller also connects to an iPod for playing your own music through the backrest's speakers. The backrest has soft foam cushioning that conforms to your body's contours and helps relieve pressure points. Plugs into AC. 31" H x 18" W x 6" D. (20 lbs.)