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. This is 4 wire type 5. DC 9-35V wide voltage operating a range 6.Low standby current 7. Power supply non-polarized input 8. Twin LED for 360 degrees visual 9. Flashing LED power indicator 10. The alarm output is relay output 11. Metal shield, anti-electromagnetic interference 12. Two-year limited warranty 13. Suit for detecting the smoke in the house, shop, hotel, restaurant, office building, school, etc...