There are four versions. Variants 0,4 mm and 1 mm reffer to thickness of the flange. Slimmer 0.4 flange should “dam” the water less. Torture test variants are with grid-wall which allows greater water throughput and doesn't get clogged as easily. But it looks almost like stringing torture test prints.

Intended to print with supports, as in the picture. Torture test has support structure modeled in as slicer would build supports through the wall-grid.

Holes are approx. 2,5 mm large. Do not use PLA, anything else should be fine. Source files are provided in f3d.