Hey, all. I'm trying to find a marble track set from when I was a kid, or something similar. Its main hook was that you built the infrastructure for the track using plastic tubing and 90-degree fasteners. Then you attached the track pieces themselves to the grid of pipes using other clamps and ball-socket joints, allowing for lots of variability in the designs of tracks.

There were ramps, loops, trampolines, etc. The pipes were blue, the track was black and the marbles were yellow.

Does anyone know what this product might have been, or at least what KIND of marble set this would have been called so I can find an equivalent?