Debdeb,
I have an Acapella made by Portex. They are not too expensive. Around 35 dollars. I got mine because the Technician who did my PFT, gave me one. I have a green one. I also was given a Voldyne 5000 spirometer. The Technician showed me how to use both, when to use them, and what order to use them in. I have been using mine for almost two years and it really helps in getting excess mucus out of your airways. I would go with the online place with the best price for a Portex Acapella (green-hi flow or blue- low flow). Which one, green or blue, that would be the physician's decision according to your PFT test results. There are different types of acapella type vibrating valve system to help with mucus removal. That is up to the individual to get what works for them. Let the forum know what you get and how you like it. Take care and God Bless!