Thera-Band Exercise Balls - Pro Series SCP-85cm-Silver Nearly twice the wall thickness of typical standard balls Burst resistant, slow deflate design is more resistant to rapid deflation vs. standard exercise ball Provides superior comfort at body contact points without excessive softness that impedes support Smooth surface, non-coarse wall design offers more comfort, less abrasion and better response Comes with a full color poster of 24 exercises and inflation measuring tape