Print in whatever filament you want, but i personally recommend something more durable than PLA.
With 30% or less infill and no top/bottom layers you can create a mesh in the bottom of the box and/or the lid.
I didn't change the lid because it thought it's easier to keep those separated. So print 2 of 'em.
Enjoy!
The author remixed this model.
Just connected 2 of the Buck Converter boxes (originally made by ZZET) together. Lids are unchanged.