All of the FlexFoam-iT! foams are flexible, but some are more pliable than others. FlexFoam-iT! III, V, VI, VIII and X are very pliable or supersoft foams. On the other hand, FlexFoam-iT! IV, 17 and 25, although still bendable, exhibit a more tight foam cell structure and are less "squishy" compared to the supersoft foam versions.