The unique ribs make the 35cm Rib-It-Ball easy to grap and prevent it from rolling out of reach. Surprisingly lightweight, the Rib-It-Ball doesn't hurt a child on impact, and it is fun and easy to throw! The "crinkle factor" in the ribs provides great tactile and auditory stimulation, while also signalling its location to a child that is blind. This is not only a great ball for children with special needs, but for all children!