Cando Inflatable Exercise Ball The Cando Inflatable Exercise Balls are used by pediatric and NDT therapists as an aid for vestibular movement and equilibrium therapy, by fitness professionals as an aid for stretching and strength programs, and even by pregnant women in birthing classes, and people with back problems. Cando Inflatable Balls have a non-slip PVC vinyl surface that is ribbed for extra security. The balls may be "under" inflated to give a soft, mushy feel or "over" inflated for a firm, bouncy feel.