Therapy Balls What Are The Colorful Balls That Expand Into Spheres Called? I Think These Are Used In Occupational Therapy.?

What are the colorful balls that expand into spheres called? I think these are used in occupational therapy.? - therapy balls

They can be used in occupational therapy for sensory problems, and were very popular at carnivals, festivals, and the circus a few years ago. I need to know what they are called, you can find it! Thank you!