Photoelectric Smoke Detector & CO Alarm, 10-Year BatteryFirst alert, 10 year, 2 in 1, photoelectric smoke detector, with carbon monoxide alarm, talking alarm speaks to indicate the type & location of directed threat, slim design, maximum protection, blends in easily with decor, patented smoke entry system allows for a direct path to the smoke sensor, helping to minimize nuisance alarms that often come from cooking smoke or shower steam, uses photoelectric smoke sensing technology that detects smoke