DAHUA KEYFOB WIRELESS/868MHZ ARA24-W2

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