SOS emergency alarm. Frequency hopping function and two-way communication technology Cloud update and automatic recovery from update failure. Button: 4 (Home, Away, Disarm, and SOS) Low Battery Alarm Carrier Frequency: 868.0 MHz–868.6 MHz Communication Distance: Up to 900 m in an open space, Two-way Encryption Mode: AES128 Power Supply: CR2032 battery Operating Temperature: –10 °C to +55 °C Battery Life: 5 years Product Dimensions: 60.0 mm × 39.5 mm × 15.0 mm