Experience double the adventure with the Quadrilla set featuring this amazing double spiral. Both sides, concave and convex, have spiral pieces, doubling the playability. When the concave side is facing up, the ball glides from the arm to the outer ring and quickly descends towards the center. With the convex side facing up, the flow of the ball is reversed. A ball thrown into the center moves swiftly from the center to the outer ring and the arm. The set includes a double-sided spiral, three wooden distribution blocks, a hole seal, an accelerator, two stabilizing rings, and eight balls. It helps develop spatial thinking and understanding of the principles of science, technology, engineering, art, and mathematics. It also fosters the child's cognitive thinking and enhances the understanding of cause-and-effect relationships. The spiraled paths create more rolling time and bring you closer to the action. The ball receiver produces a swirling sound and prevents the balls from escaping at the end of each run. By creating each colored block for a different purpose, it encourages logical and mechanical thinking in children. The toy is made from durable wood and non-toxic water-based paints, making it the perfect choice.