Feature:1. *Support three alarms: independent sound \u0026 light flash alarm, wireless 433 transmission network alarm.2. *360 degrees smoke detection and alarm, no dead angle, reliable. Built-in 90 dB sound and light alarm reminder, effectively prompting people to evacuate.3. *Adopt high-performance photoelectric two-way scattering patented technology of two-receiving \u0026 one-transmitting and high-sensitivity sensing, stable, reliable, safe and accurate.4. *This smoke sensor can work alone to realize independent alarm at home. To achieve remote control on the phone, smoke detector needs to work with Sonoff RF bridge( 433Mhz, EV1527) host.5. *Ultra-low-power microcontroller + photoelectric principle technology, long standby life battery use for 3 years.6. *Low Voltage Alarm: When the battery voltage is lower than 6.8V, a warning sound is issued to remind the user to change the battery.7. *Full snap-in patented structure, simple installation, no need for debugging and wiring. Convenient for cleaning and battery replacement.Specification:Please Note: Because of shipping limitation, battery( DC9V 6F22 ) for smoke detector not included.Features:*Support three alarms: independent sound & light flash alarm, wireless 433 transmission network alarm.*360 degrees smoke detection and alarm, no dead angle, reliable. Built-in 90 dB sound and light alarm reminder, effectively prompting people to evacuate.*Adopt high-performance photoelectric two-way scattering patented technology of two-receiving & one-transmitting and high-sensitivity sensing, stable, reliable, safe and accurate.*This smoke sensor can work alone to realize independent alarm at home. To achieve remote control on the phone, smoke detector needs to work with Sonoff RF bridge( 433Mhz, EV1527) host.*Ultra-low-power microcontroller + photoelectric principle technology, long standby life battery use for 3 years.*Low Voltage Alarm: When the battery voltage is lower than 6.8V, a warning sound is issued to remind the user to change the battery.*Full snap-in patented structure, simple installation, no need for debugging and wiring. Convenient for cleaning and battery replacement.Specifications:Power Supply: DC 9V 6F22 alkaline battery (not included) Standby Current: ≤10uAAlarm Current: ≤100mAAlarm Indication: Sound alarm & LED flashSound Level: 90dB/3MDetecting Area: 20 square meterWireless Frequency: 433MHzAPP: eWeLink Operating Temperature: -10°C ~+50°COperating Humidity: ≤95% RHItem Size: Approx. 10.5 * 10.5 * 3.5cm (L*W*H)Package Information:Package Size: Approx. 10.5*10.5*3.8cm / 4.1 * 4.1 * 1.5inPackage Weight: Approx. 120g / 4.2oz Package List:1* Wireless Smoke Detector1* User Manual (English)Package List:1* Wireless Smoke Detector1* User Manual (English)