The First Alert Red LED Flash Indicator Photoelectric Smoke Detector combines photoelectric and ionization sensing technologies into one unit to offer broad detection against smoldering and flaming fires. Recommend that for optimal protection you have both types of sensing technology in your home. This provides further flexibility in aiming the detector. This smoke alarm&acute;s trademarked Hush feature allows you to silence nuisance alarms￡? while an indicator LED and test feature let you easily confirm that the alarm is working.                                    Features            A battery powered photoelectric type smoke detector reduce nuisance alarms from cooking smoke and shower steamSpecial moisture-proof designWith manual testing￡? auto resetEasy to install￡? smt design￡? stable and reliable performanceLED indicator alarm￡? strong adaptability to environmentUnique structural design￡? dust￡? pest control￡? anti-interference from outside lightAlert and warn people stay far away from danger field when it detected smoke                                                            Specifications            Operating voltage    110V AC    <br>Static current    Max 50 mA    <br>Alarm indication    Red LED flash    <br>Sound level    ?Y85 dB / m    <br>Operating Temperature    -10 ??~ +50 ??    Operating humidity    ?ü95% RH    <br>Detecting area    20 square meter    <br>Alarm output    Sound !#!amp!*! flash alarm    <br>Size    5.04" dia. 1.50" deep    <br>Execute criterion    GB4715-1993￡? EN14604￡? Ul217    <br>                                                            Package Includes            1 x First Alert Red LED Flash Indicator Photoelectric Smoke DetectorPower Line Interface1 x User Manual                                                            Extra Info            Note:If your detector runs on batteries￡? change them when you change your clocks - at the start and end of daylight-saving time1. If your smoke detector starts chirping or beeping off and on￡? it&acute;s time to change the batteries2. You may want to consider purchasing a combination smoke / carbon monoxide detector. These units cost more but are well worth it3. If a smoke detector goes off￡? you literally have seconds to respond. There is ly no time to gather possessions￡? pets and possibly even each other. Your best response is to leave your home immediately￡? gather at your prearranged meeting place and call 911 from a neighbor&acute;s home4. Avoid getting any paint or dust on your smoke detector5. Make sure the smoke detector you choose has been tested by an independent testing laboratory6. Replace all detectors after 10 years