Universal Security Instruments Battery-Operated 9-Volt Photoelectric Sensor Smoke Detector

Photoelectric technology has quicker response in case of a slow,smoldering fire. Super heavy duty battery included, warranted for 3-years from date of original installation. 9-Volt battery operated (included). Audible low battery indicator. Round, flat installation plate 5-1/2-in. Swift installation, hardware included. Alarm and power test button. Limited five year warranty. Manufacturer part number SS-901-LR-6P/U.