This full-size, ionization, battery-operated smoke alarm is designed to protect you and your family from the dangers of smoke and fire. Smoke alarm is easy to install with no wiring is required. Alarm is powered by a 9-volt battery, providing continuous protection even during power outages. Quality design includes a test button to verify the unit's electronic circuitry, horn and battery function are working properly. The flashing red LED indicates the alarm is receiving power and a low-battery indicator chirps when battery needs replacement. Tamper-resistant feature helps deter theft or tampering with three smoke detectors per case.