The Graphite Coregeous® Ball is an inflatable air-filled sponge ball  with a unique soft-stretchy "skin" that's used in conjunction with the Coregeous® Core Exercise DVD to massage and activate your core and stretch your psoas. This special, soft massage ball allows you to gently and safely access your innermost abdominals. (approx. 22" round circumference and 7" high but can vary up to 1"). 
 
The Graphite Coregeous Ball has the same quality and material you have been accustomed to with the original Coregeous Ball, just in a new color!