Quercetti Tubo Pitagorico How much is four times four? Turn the colored knobs on the cylinder and the answer will appear on the window. Handy tool for children to learn the tables from one to ten. Specifications: Dimensions: 21 x 5 x 5 cm Package dimensions: 22 x 14 x 5 cm Material: plastic Color: yellow Suitable for children from 5 years.