Yfwsrecinoe 5 Pack Upgraded Combination Smoke and Carbon Monoxide Alarm Detector, Dual Sensor Smoke Alarm&Carbon Monoxide Detector (Includes Battery)Brand: Yfwsrecinoe Color: White 5Pack Features: Upgraded Dual Sensors to Ensure Your Safety: Compared with most carbon monoxide smoke detectors on the market, our detector sensors have a lifespan of up to 10 years, while other detectors on the market only use three years life sensors, so our products have a longer service life. The combined smoke and carbon monoxide detector uses a photoelectric smoke sensor and an electrochemical sensor to detect