How do you protect your family from a hazard you can't see, smell or taste? The short answer is Kidde. We've been making carbon monoxide alarms longer than any other company, and all Kidde carbon monoxide (CO) alarm products – from basic units to premium carbon monoxide alarms – include the company’s patented Nighthawk™ electrochemical CO sensor. Install one on every level of your home to enjoy a whole new level of peace of mind.