I want to install a filter on the outside mesh surface of my awing-type window to prevent some dust from.?

Question:coming into my room because I live on the 2nd floor on a busy main street. I need something flexible (probably cloth) that I can cut to size and attach to my mesh. What brands are there? Where can I get them from?

Answers:
These folks sell just what you are looking for...
http://www.americanairfilter.com/index.a...

You could also measure your opening and go to a hardware store- air filters come in a great many sizes,and you could probably come close to fitting your opening perfectly.

Then there is ultra low-tech... an old white t-shirt. These are cheap,easy to cut to fit, and still let in light.

Best of luck.