First Alert P910  10-Year Maximum Protection Photoelectric Smoke and Fire Detector, White Sleek, compact smoke alarm reliably detects smoke from smoldering fires Photoelectric sensor detects smoke while minimizing false alarms Built-in 10-year battery offers continuous power for the life of the smoke detector 85-decibel alarm is designed to be heard easily Single test/silence button for simple operation Complies with all current 10-year legislation in states/cities where required No Battery Changes for the Life of the Alarm; 3V Lithium Power Cell Included Patented smoke entry system allows for a direct path to the photoelectric smoke sensor Nuisance free photoelectric technology reduces false alarms that result from cooking and shower steam New sleek and thin design adds an element of style to safety