Turn the marble upside down with the Looping accessory. Experiment with how much speed the marble needs to loop-the-loop. Including the loop tile and 6 additional tracks, this accessory must be combined with the GraviTrax Starter Set. GraviTrax is a modular, electronic-free interactive track system where you can design and build your own marble runs. This STEM toy for boys and girls 8 and up, encourages experimenting with gravity, magnetism, and kinetics to propel your marble to the finish.