Battery-powered smoke and carbon monoxide detectors designed to protect you and your family from the dangers of smoke and fire. Photoelectric smoke sensor and electrochemical CO sensor can detect fast and slow-burning fires Simultaneously. This smoke alarm does not contain any radioactive material. Easy installation--no wiring required Powered by 3-volt battery (battery include) for continuous protection even during power failures Flashing LED shows alarm is receiving power Low-battery indicator 10-year life time. It includes a flashing red LED to indicate the alarm is receiving power as well as a test button to verify the unit's electronic circuitry, horn, and battery functions are working properly. During a smoke incident, the smoke alarm will sound in a repetitive manner. LED indicators: This smoke alarm is equipped with red LED indicators. Low battery trouble indication: An intermittent chirp accompanied by a red LED flash every 32 seconds indicates a low battery. Danger: If the alarm sounds, and it is not being tested, it means the unit is sensing smoke, The sound of the alarm requires your immediate attention and action. Specification 1.DC 3V battery operated (10 years battery included) 2.Photoelectric chamber for early detection from all directions 3.Loud>85dB(A)alarm signal @3M 4.Flash alarm indicator(red LED) 5.Low battery signal alarm 6.Test button for easy recommended monthly testing 7.Safety clip feature,not allow mounting of smoke alarm without battery installed 8.Ceiling mounting 9.Easy to install with mounting bracket 10.10 years product life time 11.Size: f5.28 * 1.57inch 12.Package included: 1*GS883-A Smoke Alarm, 1*User Manual, 2*Screw sets More Detail See User Manual''