USI combination alarms offer 3-in-1 protection from smoke, fire, and carbon monoxide in one compact, easy-to-install device. Designed with Sensing Plus® technology and intelligent microprocessors, these alarms deliver accurate detection and fewer false alerts. Select models feature voice notifications, quick-find alarm origination, and 10-year battery life to ensure you stay informed and protected with minimal upkeep. Ideal for whole-home coverage, combo alarms provide layered defense where you need it most.