Dow FILMTEC home drinking water RO elements are constructed using advanced automated manufacturing technology. Unlike the hand-rolled elements sold by some manufacturers, Dow FILMTEC elements are built to optimum physical tolerances, minimizing element-to-element differences. In addition, critical fastening points are sonic-welded for maximum strength and durability. For ease of installation, we also offer dry low-pressure RO elements. Finally, extensive testing ensures that every FILMTEC element we ship meets our high standards for fabrication quality.