Electrochemical detection: Monitors spaces from 20 to 40 m² for odourless carbon monoxide, alerting from concentrations as low as 30 ppm Audible warning: An 85 dB siren sounds immediately when carbon monoxide levels exceed safety thresholds to wake or inform household members Lifespan and power: The 10-year sensor includes audio and visual end-of-service alerts, running on 3 included AA replaceable batteries Function monitoring: Use the dedicated test button for monthly checks, while an empty battery indicator beeps and flashes when replacement is due Mounting hardware: Includes screws and fixings for ceiling placement at least 1.85 m from boilers, fireplaces or kitchen gas stoves