Just wasted $25. Two weeks ago I developed a cough. Was headed to deer camp and decided I needed to order a "Cough Suppressor." Went on-line, found what I wanted easily and ordered it. Knowing it wouldn't arrive in time for the weekend, I tried an experiment. Took a 0.5 liter water bottle and inserted six each, select-size (about 5" long by 11 inches wide) paper towels, each rolled up tightly and inserted them in the water bottle. Shook them so they expanded. Then I used my trusty pocket knife and vented the bottle with two holes on the rounded top portion of the bottle. Worked like a champ. Got my $25 gizmo this afternoon and it doesn't do any better than what I did.