R Exclusive, only available at Toys R Us Canada. Connect between different levels! The FlexTube will allow you to easily connect between the different heights in your tracks. What comes up, must come down and with this extension you can easily change the direction of your marbles. The FlexTube can easily be adapted for 60-degree angles, u-shapes and s-shapes. Combined with a Starter Set, the speed in your track can also be controlled. Additional height stones are included in this extension so you can build even higher. How many places on your track can you place the FlexTube? This STEM system [Science, Technology, Engineering and Maths] is an ideal one to teach kids about gravity, magnetism, kinetic energy and fun. Hit a snag? Freestyle with your own track design or use the tasks and blueprints included to help you to get started in the world of GraviTrax! Are the gravity spheres stopping or flying off before reaching the end target? Time for some problem solving. Rebuild and try something different! The GraviTrax track system can be extended indefinitely with extra track packs and add-on's - each sold separately. This set is suitable for 1+ players, ages 8 years and up. This Set includes 4x FlexTubes, 4x Height tiles and Instructions