Are you looking for an equipment transport exhaust cover that actually fits and is nice quality? 
We offer them in 3 size ranges:
Fits a 6" and under $25
Fits 6"-8" $29
Fits 10"-12" $32 
Built out of black cordura material, webbing bound with 2 #2 rolled rim spur grommets to make attaching versatile and a breeze in most situations.