Joe
Not to muddy the waters. But after reading all the post here and looking for more info for myself. I came across this product from 3M, (3m versaflo) system of components that you assemble to meet level of saftey the end user needs. Lungs, eye, ears, and face. Hope this is of some help to you. Tom P.S. After some additional read on the web, 3M Versaflo system that I like, was P/N TR 300-HIK. best price was little over $800.00. check out this link.
http://www.envirosafetyproducts.com/...-papr-kit.html