The Thera Bolly is a playful game to promote co-ordination and manipulation. The small balls stick on polished surfaces and even on glass. They suction onto each other. The 4 bases of the Thera Bolly enable small construction, counting, colour sorting and recognition. Helps to improve the motricity. Stick on polished surfaces and even on Gymnic Balls. Each set contains 4 bases and 24 top parts.