Let the balls disappear! With this set, you create the element of surprise on your course. Combine the tunnels, rails and base plates with your GraviTrax starter kit for even more combination and acceleration options. Can you keep your eyes on the ball as it rolls through the tunnels? For more information, see Gravitrax.com Contents 19 parts: 1 Manual, 2 base plates, 4 tunnel turns, 2 straight tunnel sections, 2 tunnel switches, 2 vertical U-turns, 2 Bernoulli plastic rails, 2 O-plastic rails, 2 catch baskets Can only be used with the GraviTrax® starter kit. From 8 years.