Abbr. "B/I". A cable assembly using a female multi-pin connector and multiple male cord plugs on different circuits. As Socapex-style is the most common multi-pin connector, break-ins are most commonly defined only by their male plugs, i.e., Stage-Pin break-In, L6-20 Break-In, Edison Break-In. Unlike Break-Out s, break-ins are almost always of the "even" style, with all cords the same length. If a dimmer rack or ML PD has Socapex outputs with inter-patch (pin-patch) capability, break-ins are generally not needed or used. http://www.lexproducts.com/cs/entertainment_product?id=347&market=Entertainment&productLineId=17 Audio folk call a similar device, for use with mic snakes, a fan-in, as it fans in when plugging to the audio console's inputs. From Lex Products website: Breakout Assembly (NEC Definition): An adapter used to connect a multi-pole connector containing two or more branch circuits to multiple individual branch circuit connectors.