Expand your Hubelino Knikkerbaan Pi with the 70-piece Expansion Set Hubelino Knikkerbaan Pi. This set consists of 2 base plates, building blocks, yellow sliding elements, 2 tunnels and marbles. The marble runs and building blocks of the Hubelino Knikkerbaan Pi Expansion Set Cannon are made of high-quality and durable plastic, so you can enjoy them for longer!