What it covers
The mesh panels on your windows and sliding doors. Mesh catches dust the way a filter does, and it stays there.
Why it belongs with the glass
A dirty screen sits directly between you and a clean window. If your windows have screens, cleaning them is part of seeing the difference.
Tell Robert how many
The Window Counter on this site asks about screens, so you can tell him up front.
Common questions
Do I have to take my screens down first?
No need to do anything before your quote. Ask Robert what he would like done before the cleaning day.