A while back I saw a large layout with well-organized and very neat wiring underneath. They used a round plastic cable bundling device, maybe about the size of a little finger curled up, with a slightly flat surface on the back side with a small screw hole in it. The front ring like part could be opened and then shut with a catch built into the thing so wires could be run through it (them). It could be opened up and then closed again for added wires.
Does anyone know what these are called and/or where they can be found?
Tom