1. Stops mice so they can't chew through it like plastic and can't pull it out like mesh.
2. Allows inner wall to ventilate so wall can function as intended which is to avoid mold and rot. Solutions that do not take this into account are no solutions at all.
3. Fits majority size and shape weeps with superior flexibility, home owners can easily install thus saving money.
4. Its a one time solution! Doesn't rust, looks great.