Jay came to my apartment on Friday night (during his dinner out with his family) and stayed beyond the time necessary in order to verify the alarms would not go off. He was very friendly, and professional. And when one of the alarms went off again, he returned to change out the battery again, and stayed to see if the alarm would go off. At 6:30 a.m. the next morning, one of the alarms started chirping. Jay came back on Saturday, changed out the batteries on all 4 alarms again, and stayed to see if the alarms would go off. Thank you, Jay, for being so thorough. Great service!.