4 inch pipe, cover, internal, cap

Large 4 inch ABS conduits, inside diameter just shy of 4". These also have a 1/8" diameter O-ring groove if you want to add one to keep the cover in place. These needed to be stronger because there is foot traffic in the area, and chairs are stacked near by, and the chair legs would go right though the thin/cheap plastic dust covers. These were printed in PLA+ at 50% infill, more than strong enough to stack chairs on.

Added an O-ring for additional sealing, but more so to keep the cover from easily popping out. Amazon ASIN B00A784A74, 100mm OD, 96mm ID, 2mm diameter.