b'The Oov activates core stabilizing muscles, while gently extending the spine to stimulate healthy disc lubrication.OovThe Oov activates core stabilizing muscles while also gently extending the spine to stimulate healthy intervertebral disc lubrication. From stretching to core strengthening to rehabilitation, the Oov offers significant proprioceptive benefits. Its highly durable foam complements the spines natural curves. Size S, M, L (see website to determine size best for you).Product Part # CostOov Large with Start Guide 12949 $179 USOov Medium with Start Guide 12948 $179 USOov Small with Start Guide 12947 $179 USOov Set of 3 (S,M,L) 12946 $510 US15'