jim boles
This is a personal HEPA air filtration system with a hard hat. Great for wood turners or other situations where there is a lot of dust and potential physical danger.
This 3M product is supported at the AirStream web site. The air filter and hard hat retail for around $680. I'm selling my used unit for $199. You will need to purchase the Tyvek Face Seal for $6 at the site below to complete the system. The system is being sold as a single unit. However you do not need to use the hard hat if you purchase the soft hood for $27 at the site below.

Item 231-01-30 3M HEPA Airmate Air Filter Unit
http://www.airwareamerica.com/search.aspx?manufacturer=2&category=22&log=false