Wireless Calling System with 1 Watch Receiver 1 Transmitter Water Resistant Portable Wireless Pager Call System for Restaurant Home School Item Type: Wireless Call System Receiver: Operating Frequency: 433.92MHz Operating Current: 100±20mA (Vibration + Buzzer Mode), 75±10mA (Vibration Mode) Battery Capacity: 300mAh (Included) Standby Current: 10±5mA Sensitivity: -107±2dBm Decoding: Learning Code Water Resistant Rating: IPX4 Operating Temperature: -20℃ to 60℃ Transmitter: Operating Frequency: 433.92MHz Battery Type: 1 x 23A 12V Battery Battery Capacity: 60mAh (Included) Transmitting Current: 10mA±3mA Open Distance: > 1000m / 3280.8ft Key: 1 Million Times Water Resistant Rating: IPX4 Operating Temperature: -20℃ to 55℃ Single Key: CALL