The bracket was designed for a roof with a 50deg pitch. It may not work on really shallow roofs.
It prints without supports.
As there are no fillets between the bracket and the plate (in was a hack in a hurry, there is an issue with combining a mesh [the original plate] with a solid body [my bracket] in Fusion360)
in the slicer I added two modifying cylinders where the bracket meets the plate and increase the perimeters and density of infill.
I doubt this is really needed but I could so I did.
The author remixed this model.
This is a hack of @magu ‘s EXCELLENT mounting plate for Ubiquiti APs. @manu’s plate works really well, its a great piece of design but I needed the AP mounted between the timbers inside my loft at the peak of a pitched roof.