174 / | HD | ELECTRICITY: CONDUCTORS AND INSULATORS |
137 R | DF | INSULATORS {17} |
158 R | DF | .~ With insulator-supporting or attaching means {7} |
164 | DF | .~.~ Support penetrating {2} |
166 R | DF | .~.~.~ Through aperture, penetrating element clamped {1} |
166 S | ![]() | .~.~.~.~ Stand-off insulators |