This single-feed transformer converts 277 volt power to 12 volts to provide the necessary voltage for powering a MonoRail, Kable Lite, Wall MonoRail, or FreeJack low-voltage lighting system. It can power lamps totaling up to 300 watts. This transformer is equipped with a fast acting secondary circuit breaker that will safely turn the system off should a short occur. Once the short has been removed the breaker can be reset.