Mine is also a Smartvest with the Velcro and they can be adjusted to be snug but I find them pretty easy to maneuver. Right now I use 3% saline that comes in 15 cc but am going to speak to my pulmonologist after reading these posts about increasing the saline percentage and see if it is supplied in less than 15 cc. It takes forever it seems for the 15 to be completely used. I had a CT and my doc has diagnosed MAC based on that. I had a bronch with biopsies and washings but all the results have been negative which is puzzling to me and makes me wonder if I indeed have MAC or just the bronchiectasis which shows on the CT. Has anyone else been told they have MAC without positive cultures/sputum/biopsies?