Best mains smoke alarm hard wired smoke detectors optical smoke detector

1.Easy installation and maintenance 2.Light Labyrinth with High stability & High accuracy 3.High adaptability to the ambient,with dustproof,mothproof,moisture proof and anti-white light function 4.DC 9-35V wide voltage operating range 5.The 4 wire smoke detector withLow standby surrent 6.Power supply non-polarized input 7.Twin LED for 360 degree visual 8.Flashing LEDpower indicater 9.Alarm output isrelay output 10.Metal shield, anti-electromagnetic interference 11.Our all different types of smoke detectors have Two-year limited warranty 12.Suit for detect the smoke in house, shop, hotel, restaurant, office building, school etc... More detail:https://www.firealarmfactory.com/4-wire-smoke-detector.html