TIMESETL 5Pack Stainless Steel Woven Wire Mesh Screen, Air Vent Mesh, 11.8“ X 8.27“（30 x 21cm) 1mm Hole 20 Mesh, Metal Mesh Sheet, Rodent Mesh Screen for Garden Animal Cage Net Security Cabinets Mesh

Keeps critters out of the crawlspace!

Sturdy. Excellent quality.

The holes in these meshes are extremely small, like about the width of a sewing pin or smaller. I wouldnt recommend using it to cover any floor ac vents since it blocks out a lot of air, if the holes were like two times bigger it would be better for home ventilation.

Started to rust after 3 weeks