Socapex is a brand of electrical connectors, known in the entertainment industry primarily for their 19-pin electrical connectors, commonly known as Socapex connectors, and used in film, television, and stage lighting to terminate the ends of a multicable. They are wired with six hot/live pins, six neutral pins, six ground/earth pins, and a final central pin used to aid alignment of the male end of the connector with a female receptacle. The Socapex was first created by a company called Socapex in 1961, which later on became Amphenol Socapex. "Socapex" became a brand name owned by Amphenol Socapex, the term is now often applied to similar off-brand connectors as a genericized trademark. "Breakouts" are used to connect the fixtures to the cable. The breakout consists of a male Socapex connector with six "tails" with female Edison plug, stage pin connector, IEC 60309 16 A, NEMA L5-20P 'twist-lock' or BS 546 15 A connectors. A "breakin" is the opposite, consisting of "tails" with male Edison, stage pin connectors, IEC 60309 16 A, NEMA L5-20R 'twist-lock' or BS 546 connectors feeding a female socapex connector. These are used to connect Socapex cables to dimmer packs that do not have Socapex outputs.
Amphenol Socapex is still manufacturing and selling the original Socapex. The company also manufacturers a wider range of robust multi-way electrical connectors available in various standard and custom configurations. These are used for other high-current applications within live events; commonly for trunk cables to connect PA speakers or stage wedges to amplifiers, usually using breakin and breakout cables to NL2/NL4/NL8 or EP5. While some companies use Socapex as a rigging motor power cable, this is generally not recommended as differences in voltage (i.e., 400 V vs. 230 V) can be misinterpreted, causing extensive equipment damage.
Please note that the image above displays CEEP connectors who were the first company to introduce the mono piece backshell into the market many years ago.