I purchased an AR 2 recently and it works perfectly. One word of caution however; this unit requires a regulated 12 volt power supply. Don't wire it directly to a toy transformer that is unregulated. You will be sending 18 to 20 volts to this unit and it will be damaged. Circuitron also sells a PS 2 regulator which I used to reduce the voltage to 12 and have had no problems. Terrific item and Circuitron offers excellent customer service.

What pleasure after successively installing the AR 2 to operate a trolley. Running in the background on the layout after setting the AR 2 delay time 0-1 minute,and adjusting the speed on the controller, the trolley starts, and stops and returns automatically (set it and forget it) it's amazing, and quite rewarding. I purchased 2 of the AR 2's here on Hobbyinc,and now have 2 trolleys running, so very rewarding. Note:William Casper appears on here with numerous pictures and reviews,I have him to thank for his AR 2 how to demonstration on youtube, a fantastic job.