Review on 🔥 UL Listed Photoelectric Smoke Detectors – 2 Pack Fire Alarms, 9V Battery Operated (10 Year Life Time) by Major Genesis

First both supplied 9 volt batteries were empty. Double checked with a multimeter. So I replaced them with my fresh batteries. I checked the date and thought it was an old device. No, manufactured in April 2020.2, after you fix the base to the ceiling, you need to screw the detector to the base. Can't turn at all. 3rd, 1 of 2 detectors failed. It only flashes and makes no sound after 5 seconds, 10 seconds or 15 seconds during the test. Both detectors return to Revain. I'm not sure if he will return to Zhejiang, China or not.