Wireless Calling System Sensitive Wireless Restaurant Table Call System with 20 Table Bell Buttons and 1 Receiver for Hotel Offices UK Plug Item Type: Wireless Call System Display Receiver Parameter: Work Frequency: 433.92MHz Material: ABS Working Voltage: DC5V1A Working Current :<130mA Standby Current: <550MA Receiving Sensitivity :-105dBm Decoding: Learning Code Water Resistant Rating: IPX4 Operating Temperature :-20℃- 60℃ Button Transmitter Parameter: Work Frequency: 433.92MHz Battery Type: CR2032 Battery 2 (included) Single Battery Capacity: 225mAh (included) Transmitting Current: 10mA±3mA Standby Current: <1uA Open Distance: >200 meters Button: 1 million times Water Resistant Rating: IPX4 Working Temperature: -20 ℃-55 ℃ Single Button: CALL