A generator interlock kit (or just interlock kit) is a device designed to allow safe powering of a home by a portable generator during a power outage. It is a less-expensive alternative to purchasing and installing a dedicated transfer switch. The kit achieves the same function by adding an external interlock onto an existing breaker panel that allows the main breaker to be turned on or one designated load breaker to be turned on, but not both at the same time. The interlocked load breaker is repurposed as the "backfeed" breaker, and a generator is connected to it (wired directly or through a power inlet).