StabilityPads are large enough (12-3/4 inch diameter) and sturdy enough to be used by different ages in numerous ways, from the fun of stepping stones for Sportime WobbleWalk to serious exercise for core strength development. They can be sat, laid and, most significantly, stepped on. StabilityPads can be inflated or deflated to whatever desired firmness is desired, from practically flat to an almost rounded 10-1/2 inch height. The activity (and reshaping) options are endless! StabilityPads are sold as set of 6 in assorted colors.