The rail attachment is clipped onto a normal GraviTrax rail, then you can continue building directly on top of it. The rail attachment has a hole so that the balls can also fall through a funnel or free fall onto the rail below.

Works well with "light" components, however, elements such as the Power Starter or the Elevator are too heavy for the rail and the holding curve stones.

See it in the Video:
https://youtu.be/C9HXfEzPqLw

Scope of delivery:

1x rail stone