Just add this 9V Train Motor and #4548 Speed Regulator to your train engine, build your track layout, and your train is ready to roll!* * #4548 Speed Regulator and train tracks sold separately. 9v LEGO Trains require 9v tracks and rails, which conduct electricity. Compatible tracks and rails are #4515, #4519, #4520, #4531 and any track collections consisting of these item numbers. When motorized with a 9v motor, this engine will not run on LEGO RC Train tracks (#7895, #7896, #K7895, #K7896).