Gebhardt-Stahl has made steel GREEN .. in more ways than one. Namely we incorporate butyl, the green sealant, into our duct profiles. This gives air ducts an extremly good seal, makes them energy efficient and ultimately environmentally friendly i.e. green. All this saves time and money during the installation process. Therefore, at Gebhardt-Stahl, we bring "Made in Germany" right up to date and make it relevant to today`s industry.