I used the plastic fasteners that came with mine but you don't need them. Go to your hardware store and look for black ( I think you are painting your diffusers black) automotive type screws with built on washers or large heads. A number #10,12, or 14 will work just fine. 1/2" to an 1" long will work.



The difussers are a bit tricky to get them lined up for perfect fit due to the tape wants to stick everywhere but where it should!

James