Tobbles.

Tobbles has a great modern design for a stacking, balancing, and however you want to use it toy - and the possibilities are many. Each of the colorful 6 spheres has a dual-textured surface and there is a pleasant heft to each weighted piece. The 6 Tobbles pieces can be carefully balanced, suitably nested, and more. Designed for encouraging sensory exploration, hand-eye coordination, fine motor skills, and visual spatial awareness.