Victaulic style 647 IPS to CTS dielectric transition fittings are typically used to join carbon steel or stainless steel pipe to copper tubing with one fitting. The fittings provide a set distance between the metals being joined while maintaining a minimal electric potential between the fitting and surrounding piping. The style 647-TT (thread x thread) is only available in sizes from 1/2 to 4 in or 15 to 100 mm.