This is not a typical stack-and-nest toy. The weirdly-shaped pieces can be stacked and arranged any way you want. The vibrant colors are fascinating. The unique contours are inspiring! But then, nest them together, pull up on the smallest, and let your jaw drop. The whole thing stretches into a tall, spiraling tower! - It's like magic! Beautifully un-intuitive design inspires hours of tactile discovery with SpiroKu.