THRIVE pink balance boy. It's not a sphere, but an electric seat that moves to train your core. It's safer and takes up less space than a balance ball. Height is about 25 cm. Diameter appears to be about 50 cm. Comes with a convenient AC adapter. - Brand: THRIVE - Color: Pink - Accessories: AC adapter - Model number: FD-091 Use it as a chair in your living room for exercise. Thank you for looking.