what is
All I was able to find about this was a mention of it in this book, but it gave no specific name to the product:
<a target=_blank class=ftalternatingbarlinklarge href="http://books.google.com/books?id=BGefk9zBqlgC&pg=PA39&lpg=PA39&dq=percussor+pack+cystic+fibrosis&source=bl&ots=YNfBnRpf3y&sig=LC3QVaT2Sdz0gcm56bfbrasYGRc&hl=en&ei=WsYfStyDMuCwtgfNxL26Bg&sa=X&oi=book_result&ct=result&resnum=1">citation from book: Cystic Fibrosis, a Guide for Patients and Families (Dr. David Orenstein)</a>