Grundig Smoke Detector

In the event of an alarm, there is an audible and visual indication. An acoustic 90 db sound from the internal siren will be heard and the light will blink.During the smoke alarm is alarming, you push the test button, it will be paused the smoke alarm for approx. 10 minutes. The red LED will still flash every 10 seconds, it indicates the smoke alarm is working in the hush mode.SpecificationsBattery: 9v DCOperating temperature: 4-38 degreesOperating humidity: 25-85%Smoke sensor: OpticalAlarme volume: 85dbHush status: Red Led flashes every 10s / Alarm Silence 10 minutesStandby status: Red LED flashes every 43sLow battery status: Beep every 43sLifetime detector: 10 years