Install a boyau: make sure it ha a diameter of at least 50 mm, with a smooth inner wall and a traction fil de fer in it. The canal should run from outside to inside (all the way into the house). Idéale malgré les voyageur, elle-même avance un liaison fiable https://www.becharge.be/be-fr/Acheter/cartes-cadeaux-LEGO-Belgium-3-708