» Eco Products, Inc.
   Commercial HVAC ductwork and accessories.
   http://www.ecoduct.com/

» Fabri-Tech, Inc
   Custom steel fabrication specialists. Carbon and stainless ductwork, chutes, hoppers, bins, launders, tanks, breeching, and plate work.
   http://fabtechnology.com/

» Nystrom Building Products
   Manufacture access panels, floor and roof hatches, louvers and expansion joint systems. Includes downloadable CAD drawings and CSI specifications.
   http://www.nystrom.com/

» Pal International S.r.l.
   Manufacture foam based pre-insulated ductwork . Product specifications, and completed installations .
   http://www.koolduct.com/

» Truduct Products Limited
   Stockists of ductwork and associated products. United Kingdom.
   http://www.truduct.co.uk/

» USF Fabrication
   Fabricate and supply access doors and hatches.
   http://www.usffab.com/