Why you need the GENTEX Smoke Alarm with visual signal. Not unlike the warning systems in businesses and hospitals, this detector is both very loud and very bright, sure to capture your attention while asleep or awake. It’s a photoelectric smoke detector designed to give reliable early warning of the presence of smoke where both audible and visual alarms are required. This Strobe Smoke Detector - Hard Wired Version is hard-wired and easily installed by your favorite electrician.