Technical specifications:

Receiver Operating Voltage: AC 110V-240V

*Plug: US / EU / UK
Battery in transmitter: 12V 23A alkaline battery (Included)
Power consumption of transmitter <10mW
Wireless Range: 1000 ft maximum (Open Space)
Internal Sounds: 36 Chimes
Volume range: 4 adjustable levels (0db to 110db)
Working frequency: 433.92MHZ ± 0.5MHZ
Waterproof (Transmitter): IP44

Operation temperature:-10～50°C(14～122°F)