The USI MI106S Smoke Alarm features a 10-year sealed battery for permanent power and continuous protection in the event of a power outage. Universal Smoke Sensing Technology detects fast flaming fires and slow smoldering fires while microprocessor intelligence virtually eliminates nuisance alarms for the perfect two-in-one home safety protection. Studies show that one of the leading causes of preventable death due to smoke and fire is a deactivated or inoperable alarm. This USI Hardwired Smoke and Fire Alarm is equipped with a 10-year sealed battery that provides a decade in peace of mind, while removing the need for battery replacement. Permanent Power allows you to simply install and activate the alarm for protection that will last for up to 10 years. This gives you maintenance-free battery power, eliminating low battery chirps and the need to buy replacement batteries throughout the life of the alarm. Purchasing a permanent power alarm saves you money and reduces environmental impact by providing environment friendly protection. This USI Smoke Alarm reduces environmental waste and eliminates disposal of up to twenty 9-volt batteries.