The Monorail 300 Watt Single Feed Magnetic Surface Mount Transformer converts standard 120 volt line-voltage to 12 volts to provide the necessary voltage for powering a Monorail low-voltage lighting system. It can power lamps totaling up to 300 watts. Finish available in Satin Nickel or Antique Bronze. The transformer is concealed inside a decorative housing 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 unit can be reset by simply flipping the wall switch off and back on. The shortest rigid standoff that can be used with this transformer is the 4 inch rigid standoff, sold separately. If dropping the rail more than 4 inches below the ceiling, order the desired rigid standoff length and one compatible power extender, sold separately. ETL listed. 9.1 inch diameter x 4.8 inch height. Dimmable with a low voltage magnetic dimmer, sold separately.