Exercise balls are used to improve balance, coordination, flexibility, strength and even just for fun. Balls are used as aids for vestibular movement and equilibrium therapy, by fitness professionals as an aid for stretching and strength programs, as seats, and even by pregnant women in birthing classes. The CanDo balls have a non-slip surface that is ribbed for extra security. The balls may be "under" inflated to give a soft, mushy feel or fully inflated for a firm, bouncy feel. Available in various color-coded sizes and 3 styles: standard balls have a 300 lb capacity, ABS Extra Thick have a 450 lb - 600 lb capacity range, and Super-Duty Super Thick balls have a 600 lb capacity. Pump not included.