This is a tunnel for our crayfish tank for him to be able to hide underground. It has ridged steps so this should work for other critters or fish too.
Dimensions:
Bottom to top: 76.2mm
Bottom to sand: 57.15mm
Total width: 438.55mm
Depth (front to back): 79.7mm
Printing details:
I used Overture Matte Light Brown PLA.
Printed on its side in 0.3mm layers (Prusaslicer 0.3 draft).
In order for it to fit on my Prusa MK3 I cut it in half and welded back together with a soldering iron. See the included the 3mf of it pre-cut and plated.
Another suggestion would be to connect the two models together in the slicer to make one smaller, continuous piece.