Smart Smoke Alarm Kit GS559AH •Safe and Reliable: Comply with CE EN14604 (Certified by Intertek). Alarm at maximum 85dB. •Alarm Linkage: When one alarm detects smoke, all alarms will chirp to remind you. (Purchase multiple smoke alarms.) •Alert: Your Meross app or Apple Home app will receive an alert instantly when danger happens. •Battery Replaceable: 2 x 1.5V AA batteries included and replaceable. •Automation: Set triggers to control other Meross devices in the Meross app. •Smoke and Overheat Detection: In addition to smoke detection, it can also detect overheating. When the temperature is too high (54 - 70?), it will chirp to remind you. •Control Up to 16 Devices: One hub is able to control 16 meross devices (sensors, detectors, thermostat valves) at same time. •Works with Apple HomeKit and is compatible with SmartThings.