Best For: 
People with wider and more naturally rounded upper backs and naturally flatter lumbar curve and narrower hips and who like the feeling of being held by the backrest of their chair. 
 
Benefits and Features: 
Provides pelvic positioning & stability with wrap-around lower back feature. 
Flat seat prevents side pressure on legs which allows muscles to let go and relax and help prevent sciatica.
Flat seat allows wider range of differ ently sized users to use the same chair.