The HEIMAN Indoor Siren Zigbee ensures you’ll hear security alerts from your smart home sensors loud and clear, with a maximum volume of 95 dB and a flashing red LED. It plugs into any Type C power socket and features a built-in backup battery to stay functional during power failures or tampering. Features: compact plug-and-play design, Zigbee 3.0 wireless technology, backup battery for up to 1 hour, and easy installation.