Specifications: Types of hazards detected: smoke Low battery indication: Yes Alarm Volume Level (dB): 85 TEST button: yes Alarm mute: no Fault Indication: No End of Life Signal: No Dimensions - width: 107mm Sensor life: 10 years Dimensions - height: 35mm Sensor Type: Photoelectric Device Type With Battery: Device Product requires batteries: yes Built-in battery: no Battery added to product: yes Battery Type: 6F22 Number of batteries: 1 The sensor is a device designed to monitor enclosed rooms for the presence of smoke and for early detection of fire. The photoelectric sensor detects visible smoke generated in the flameless initial stage of fire, optical and audible notification, the TEST button allows you to check the correct operation of the sensor, low battery signaling, compliance with EN 14604:2005 + AC1:2008 confirmed by the BSI-KM550646 certification body. ** Illustrative photos.