Return Air Vent and A/C Filter Grille by patterncut on DeviantArt (deviantart.com)
Here are some factors which will drive you to choose these new grilles and vents over the old and standard iron and metal grilles. read briefly
https://www.deviantart.com/patterncut/art/Return-Air-Vent-and-A-C-Filter-Grille-787443813