"Power Supply: Low-consumption battery operation
Notification: 90db on-site siren
Radio Frequency: 868MHz
Transmitting Distance: ≤ 100m (open area/ no interference)
Operation Condition: Temperature  -10°C/ 14°F ~ +55°C / 131°F

Small size, safe and convenient to use.
DIY self-installation
Pair accessories manually for easy operation.
52 built-in doorbell songs+4 adjustable volume"

"Smart sensor doorbell (main unit) Power:
DC 6V (two 3V CR123A batteries)
Volume: 90dB
Standby current: 170uA Temperature: -10°C +55 °C

Doorbell button
Power: DC 3V (two 3V 2032 button cell)
Wireless transmission distance: ≤100m (in an open space / with no interference)

SOS button (panic button)
Power: DC 3V (two 3V 2032 button cell)
Wireless transmission distance: ≤100m (in an open space / with no interference)"