The Monorail 300W Extended Surface Mount Transformer by Edge Lighting Monorail single feed, 300 watt, 12 volt, extended surface mount magnetic transformer converts 120 volt input to low-voltage 12 volt output. The decorative surface mount transformer mounts to a standard 4 inch square electrical box with round plaster ring or octagon electrical box (not included). Available in 6, 12, 24, 36, 48 and 96 inch heights. Use with corresponding standoff's. Maximum 300 watt load. Is LED compatible with 12 volt AC LED's. Finish available in satin nickel, polished nickel, or antique bronze. ETL listed.