A tough rubber shell and has a 70% butyl bladder for superior airtight inflation. This high-optic yellow color and Crosshatch surface pattern of the ball provides children with an Ideal color they can easily see and a texture they can comfortably grip. It features a 2-ply construction that is essential to Maximize the air retention of natural rubber. The Flex Matrix Grip pattern is formed by thousands of hexagonal cells that freely flex under the pressure of grasping. Features Size - 8.5 in. Set Of 6.