GraviTrax Extension: Color Swap

Add a magical color-changing effect to your marble run with the GraviTrax Color Swap. Hide a marble inside the tunnel; the momentum from an incoming marble propels the hidden marble out the other side, creating the illusion that the marble changed color. Comes complete with instructions, three Color Swaps and three marbles (red, blue, green). Designed to combine with any GraviTrax Starter-Set; GraviTrax construction sets use STEM-friendly concepts and are for girls and boys ages 8 and up.