Laminar flow hood is used, about 20 years old, and is located in Wisconsin. It is a Baker Edgeguard stainless steel hood, which in my opinion is the best.  This belongs to a Listserv member so you must contact him for details.  If I still lived in Wisconsin, I would seriously think about getting this.  No idea condition of the filter.  Price negotiable.    Contact Chris at chrispoad1@hotmail.com