About this item Accurate & Sensitive: This smoke detector adopts an advanced photoelectric sensor that detects smoldering fires more quickly and accurately, ensuring no delay in alerting you to danger 10-Year Battery-Operated Smoke Detector: A 10-year irreplaceable battery is installed to ensure the alarm is always online and helps avoid the hassle of frequent battery changes Flexible Installation: Easy to install this mini smoke alarm with the provided screws or 2-inch-diameter adhesive tapes, or magnetic adhesive pads (not included) Self-Check: Automatically checks its battery and critical circuits every 60 seconds to ensure it is functioning properly. When the battery power gets low, a low-battery notification will inform you it is time to replace the whole unit Guaranteed Quality: This smoke alarm is housed in an upgraded ABS material that is both flame retardant and corrosion resistant; we provide a 60-day money-back guarantee and a 5-year warranty