The seller shipped on time and the unit arrived well packaged. The installation was very easy and everything worked great. The next morning we started our journey. After about 2 hours of driving, one of the sensors went out, indicating that the air pressure in one of the tires had dropped (and there was none). About 30 minutes later, a second pressure alarm went off in the other tire. And about 1 hour later a third bus alarm was generated. I realized that the problem was actually dead or dying batteries. We stopped at a local store and bought replacement batteries for about $40. After less than a day of use and the excitement that our connections weren't working, the actual cost (at least for now) of the operating system was over $170. Latest update: we can no longer turn off alarms and the device won't turn off.