Yy Ball (Aka Ying / Yang)
TWO half-Balls bolted together from the inside. Very strong! These will not come apart under aggressive treatment. All metal hardware is Stainless Steel and completely internal. We have to have access to the inside to assemble this toy so there MUST be holes in the outer wall. You can specify (2) different colors as well as (2) different wall thicknesses if you like.