Sigma Plastronics, Inc., is the formulator and supplier of NO. 1 VARY FLEX EPOXY, TYPE HV, a two-part epoxy resin system used by microwave connector manufacturers worldwide to captivate the center conductor in SMA and other connectors.

VARY FLEX HV was developed over thirty years ago at the request of Omni Spectra Corp., for use in their SMA resin-capture design. Formulators from Sigma Plastronics worked with engineers from Omni Spectra to generate the ideal resin characteristics for this application. Since that time the resin capture technique, and the use of VARY FLEX HV, have spread throughout the industry.