Remote 300 watt, 12 volt, plug-in magnetic transformer converts 120 volt input to low-voltage 12 volt output for powering Monorail systems. Needs to be installed in an accessable location, such as an attic or in a closet. To prevent voltage drop it is best to keep the transformer within 20 feet of the power feed canopy or junction box. Some buzzing may occur at low levels and may be reduced with a de-buzzing coil, sold separately. Is LED compatible with 12 volt AC LED's. ETL listed