The playground ball that lasts! Our ULTRA ball is guaranteed to keep its shape and stay inflated longer than your typical use-and-replace playground ball. Like a high-end basketball, each ULTRA ball features a butyl bladder for maximum air retention, a full layer of windings for shape retention and a foamed rubber outer layer for extra softness! Measures 8-1/2″ diameter. Set of 6, one in each Spectrum color.