The Kidde P3010B-CA is a 10-year, sealed battery, smoke alarm with photoelectric sensing technology and Hush feature. The 85dB alarm tone is accompanied by a voice warning feature. The alarm will automatically activate when it is attached to the mounting bracket; there are no pulltabs, no switches, everything is automatic. At the end of alarm life, the unit will chirp, indicating the alarm is in need of replacement. The P3010B-CA contains a 10-year tamper proof battery that eliminates the need for battery replacement, and ends worry of unauthorized battery removal. The alarm provides continuous protection from smoke and fire, even during power outages