I use a nebulizer and have always felt rushed with my delivery system because it was creating mist the entire time it was on and I rushed thru the treatment to not waste the drugs. Lots of vouching and blow back from that rushing. Respiratory therapist just gave me a new mouth piece that only mist when I breath in (closed system) so the medicine isn't being wasted. Much less stressful and relaxing and cost effective!!!! If you look at he too it can be closed or open.