Metal Boxes: Typically galvanized steel, used with armored cable (BX) or metal conduit (EMT/RMC). Indoor Device Boxes: Designed for standard switches and. Power connectors are the simplest type of electrical connector. Power connectors come in a range of sizes, for everything from low to high voltage circuits. Electrical junction boxes play a critical role in protecting wire connections, organizing circuits, and ensuring electrical safety in residential, commercial, and industrial systems. By type: Click on an appropriate item on the "Select the class" on the left. These enclosures provide both a protective housing for electrical connections and a secure mounting surface for electrical. Audio connectors are used to affix cables to other audio equipment, providing electronic signal transference and grounding protection.