Cute little tank

I love those wee little powerheads, I was trying to figure out how to put one in my nano but it really doesn't need one, I just wanted one cuz they were so cute
One question, I see one of the lids you have on there has some sort of mesh screen on it. I'm thinking I might have to invest in some sort of lid, is that screen part of a reptile setup or did you build it? If so where did you get the screening? Its not the same stuff that you use for screen doors is it, it looks a bit larger. I was wracking my brain last night trying to figure out something that was less unsightly (and smaller holes) than eggcrate but larger than screen door screening.
Any ideas?