Wireless Restaurant Service Calling System 1 Watch and 4 Button Pagers Waterproof Restaurant Pager System for Restaurant Hospital Hotel Item Type: Wireless Restaurant Service Calling System Material: ABS Watch Receiver Parameters: Operating Frequency: 433.92MHz Charging Voltage: DC5V Battery Type: 300mAh Lithium Battery (included) Operating Current: 100±20mA (Vibration and Buzzer Mode), 75±10mA (Vibration Mode) Standby Current: 10±5mA Receiving Sensitivity: -107±2dBm Decoding: Learning Code Waterproof Rating: IPX7 Operating Temperature: -20℃ to 60℃ Pushbutton Transmitter Parameters: Operating Frequency: 433.92MHz Size: Approx. 60x60x13mm / 2.4x2.4x0.5in Battery Type: 2 x 240mAh CR2032 Batteries (included) Transmit Current: 10±3mA Standby Current: <1uA Open Distance: >100 Meters Keystroke: 1 Million Times Waterproof Grade: IPX4 Operating Temperature: -20℃ to 55℃ Single Key: CALL