I was already using an Azatrax MRD2-s infrared control to automatically throw switches in and out of loops as trains approach. I have two loops with a short section between. I use the short section as a reversing section rather than using reversing loops. (one loop is actually the rest of the layout with switches and multiple paths, so I did not want to switch that power). I added an Azatrax MRAPR dpdt relay that is controlled from the MRD2 detector. Since I was already automatically controlling my switches, adding the relay for about $15.00 allowed the power to auto-reverse as the switches realign.