Because it has a chain that will pass through it, we were afraid the chain would break the acrylic lids with the friction of movement. We developed a solution in which the chain will pass through an inner pipe tube (5 cms. Diameter) and then there is a protection piece of PVC (a collar) in the juncture of the inner tube and the lids. We made a smaller version of it, pushed it around and it resisted well! We also decided that I would use a galvanized plastic coated rope wire, which is perfect for this kind of interaction and also esthetically pleasing to me.