Wireless Watch Pager 1 Watch Receiver 20 Pagers Wireless Calling System for Hotel Restaurant Workshop Item Type: Wireless Watch Pager Material: ABS for SU R169 Watch Receiver Parameter: Operating Frequency: 433.92mhz Working Voltage: DC3.7v Battery Type: Lithium Battery Battery Capacity: 400mah (included) Working Current: 57ma ± 10ma (buzzer Mode) 95ma ± 10ma (vibration Mode) Standby Current:<8ma Power off Current: 180 ± 5ua Receiving Sensitivity: - 108dbm Decoding: Learning Code Waterproof Grade: Ipx4 Working Temperature: - 20 ℃ to 55 ℃ for SU C01 (black) Button Transmitter Parameter: Operating Frequency: 433.92mhz Battery: DC12v Battery Type: Alkaline Battery (23A 12v Battery) Battery Capacity of Single Receiver: 60mah (included) Emission Current: 10ma ± 3ma Standby Current:<1ua Open Distance:>200 Meters Button: A Million Times Waterproof Grade: Ipx4 Working Temperature: - 20 ℃ to 55 ℃ Single Key: Call