The Smoke Alarm with built-in photoelectric sensor technology will reduce the nuisance alarms commonly found in kitchens and will effectively detect slow smoldering fires. The blinking LED indicator on the smoke alarm will confirm that the alarm is receiving power. The silence/test button allows you to both silence a non-threatening alarm and test the smoke alarms functionality. The smoke alarm is easily mounted on the ceiling or the wall. Keep Your Home SafeDetects smoke in your home and emits an audible warning. Photoelectric SensorReduces common "nuisance" alarms, more effective at detecting smoldering fires which smolder for hours before bursting into flame. 360° Automatic DetectionProvides 360 degrees of direct access to the smoke sensor. Button ControlTest/silence button silences a non-threatening alarm and allows you to test the unit's functionality. Easy InstallationComes with a locking feature for tamper resistance which makes it a great choice for hotel/motel application. Specifications Name Smoke Alarm Sensor Photoelectric detector Working Voltage 9V battery 12V DC (not included) Detection Area 80m²(with the installation height of 6m-12m), and 60m²(with the installation height less than 6m) Alarm Output relay output N.C., DC 28V, 100mA Installation Ceiling Mounted Working Current < 10mA Buzzer >85dB Working Environment -10℃ to 50℃ Humidity