When the engineers at Ohio Brass took a critical look at transmission insulators, they found a better way to design and manufacture them. Ideas began to build on each other until an insulator with greatly improved resistance to moisture penetration was designed.

A revised and improved electrical shielding design in the end fitting of the new Quadri*Sil silicone-rubber, direct-bonded transmission insulator reduces the possibility of corona cutting, in which the polymer material in an insulator is damaged. This allows moisture to come in contact with the fiberglass rod, which also can result in brittle fractures.

Hubbell Power Systems also developed the insulator to reduce the probability of moisture ingress and resulting brittle fractures. The end of the weather-shed housing is designed to fit into a counterbone within the end fitting. An exclusive four-point seal was also developed.