OK. I was under the impression it was the IR controller or the activator track which is what I have. The power lock on is on the full length piece and then there are two 5 inch pieces with a 'break' in the outside rail.
http://www.lionelstore.com/FasTrack-Accessory-Activator-Track-Pack-681317Not trying to question just trying to learn since there will be other accessories in the future I would think.