It fits 80mm zinc gutter (popular in France), but you can easily adjust the size as you'll find the Fusion360 file included. The outlet pipe fits inside a 32mm PVC tube (inner hole 27mm).
Print with PETG or better (PLA works but after few years it warps), 0,2mm, supports for the outlet pipe and the filter (STL upside down), brim recommended for the main body. In general, better to use the 3MF file.
The author hasn't provided the model origin yet.