The First Alert SCO501CN3ST Wireless Interconnected Smoke and Carbon Monoxide Alarm is a reliable safety device that provides protection against fire and carbon monoxide. This battery-operated alarm features a powerful 85dB sound, ensuring that you will hear it when danger is present. A unique voice alarm not only alerts you but also indicates the location of the potential threat, making it easier for you to respond quickly. The advanced technology allows this smoke and carbon monoxide detector to connect wirelessly with other compatible First Alert alarms installed throughout your home. This means that if a problem arises in one area, alarms in other areas will alert you too, even if they are on a different floor. Designed with a photoelectric smoke sensor and an electrochemical carbon monoxide sensor, this device effectively detects different types of smoke and the presence of carbon monoxide, enhancing your home safety overall.