I am upset that the first month of having the interlock I had nothing but trouble from it. I kept having to go to file a claim 7 times in one month. It cost $75 each time which equals $650 + the time lost for when it failed me at home trying to go to work. I got one claim cleared. Its just a money game for these people. Anyways, after getting my first monthly calibration 3 weeks into it I have had no trouble from it. Maybe it was just not calibrated properly, but it still cost me $600.