Calvin's 4X4X6 Cuboid Cube Calvin's 4x4x6 Cuboid Puzzle is a unique rotational puzzle that puts a new twist on your favorite puzzle cube Much like a classic cube, the goal is to match the colors on each side Each time you rotate this cube, it changes shape, creating new challenges with every turn Measures 2.35"2.56"2.56" Safe for ages 3 & up