The Combination Smoke & Carbon Monoxide Alarm by First Alert is a hardwired interconnect detector that provides precision detection for both smoke and carbon monoxide. With dimensions of 5.5" in diameter and a sleek white color, this alarm is designed for easy installation and reliable performance. It operates on a hardwired power source and features an ionization sensor for efficient detection, making it an essential component of any home security system. Built with a precision detection style, this alarm offers peace of mind knowing your home is protected from fire and carbon monoxide hazards.