Marble Genius Tubes Add On Set for Marble Run
- 30 see-through marble run tube pieces allow you to see all the action.
- Standard toy size marbles (5/8 inch or smaller) work with this set (no marbles included with this set).
- Compatible with Marbulous Marble Run Toys including our Marble Genius Marble Run Starter Set (60 pc.), Super Set (85 pc.), Extreme Set (125 pc.), & 8 Accessory Sets.