The First Alert SCO501CN-3ST Combination Smoke and Carbon Monoxide Alarm with Voice Location detects both smoke and carbon monoxide in a single device. The alarm interconnects with up to 18 other First Alert enabled alarms in your home to create a wireless safety network. The photoelectric smoke sensor is designed to reduce false alarms from cooking smoke or shower steam while remaining sensitive to real danger. The advanced electrochemical CO sensor detects carbon monoxide leaks from multiple sources, including faulty fuel-burning appliances. A loud 85-decibel siren and a voice alarm with 11 programmable locations indicate where and what the threat is. Gender: unisex.