Ziina Twisty String Cube

Ziina Twisty String Cube

A puzzle ball with a knot at its heart. Inside the clear shell, colored strings are tied together, and every twist of the ball moves them. Work out the turns that untie them, or, as the box puts it, unlock the knot.

It measures 8.3 cm (3.27 in) and weighs about 118 g. The see-through shell with yellow, green, red and blue caps lets you follow the strings as you turn. It comes in a color box and suits ages 6 and up.