2pcs Smoke Detector 10 Year Battery, Fire Alarms Smoke Detectors Ultra Thin

Activate Before Using>>> Press the test/silence button and hold it for 3 seconds until the led indicator lights up, then release the button immediately. Smoke alarm will generate a beep to indicate activation succeed. Activation failure, smoke detector won't work.
Ultra Thin Design>>> The thinnest smoke detector in the world, only 0.91 inch thickness, DIA 4.53 inch, portable design, suitable for motorhome and travel. Non replaceable 10 years lithium battery, you don't have to to worry about replacing battery.
Self-Test Function>>> Smoke detector will constantly monitor itself, replace manual weekly testing. If weak battery is inspected, smoke detector will warn you by 85 dB loud soud with flashing red light, please change battery in 30 days.
Non Disturb at Night>>> According to surrounding light, thin smoke detector will adjust LED light brightness. To prevent disturbing your sleep at night, led light will be dimmed in the dark. If low battery, it will turn to 10-hours non-disturb mode