Only qualified contractors approved by Guardian Fiberglass, Inc., may install and market the UltraFit DS System. Any installation must be done in accordance with all product label instructions, as set forth by Guardian Fiberglass, Inc., as determined by its testing. Guardian fiberglass also must be used during installation.

Airtightness test results have not been released as of this writ­ing. It also has not been determined if airborne fiberglass particles released during installation are problematic.