Specifications:

• working area: 60 square meters
• wireless transmission distance: 150M(open air)
• transmitting protocol: 1527
• sounder level: 85dB
• rf frequency: 433.92
• note: Need work with sonoff bridge
• Model Number: Wireless Smoke Sensor Detector
• low voltage alarm: 6.8V
• installation height: 6M
• function 3: works with Sonoff Bridge Wifi Google/Smart Home Alexa
• function 2: Fire Alarm System Security works with Sonoff Bridge