Photoelectric smoke detectors achieve fire prevention by monitoring smoke concentration， it is a kind of technologically advanced， stable and reliable operation sensor， widely applied to a variety of fire alarm systems， the performance is much superior than gas sensing resistance fire alarms.<br>Features:<br>Microprocessor control<br>With manual test / reset function<br>Low battery display<br>With mute function， low compensation， temperature compensation and low battery indication functions<br>Anti-RFI， dust-proof， pest control， anti-white light interference<br>Can wired interconnect 40 pcs smoke detectors at the same time<br><br>Technical parameters:<br>Operating voltage: 220V power supply (9V battery back-up)<br>Operating temperature: 40 °F ~ 100 °F (4 °C ~ 38 °C)<br>Operating humidity: 5% to 95% RH<br>Alarm output: sound and light alarm<br>Sensitivity: 3% / m<br>Alarm sound pressure: 85dB / 3m<br>Product size: Φ128 * 38mm<br>Material: ABS<br>Color: White<br><br>1 x Smoke Detector<br>1 x 9V Battery<br>1 x Connecting Wire<br>2 x Screw<br>2 x Bolt<br>1 x English User Manual<br>In Color Box<br /><img src="http://img6.eachbuyer.com/x9/p100/cb409_1.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/cb409_2.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/cb409_3.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/cb409_4.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/cb409_5.jpg" />