4 in 1 Wireless Calling System with 4 Watch Receivers Water Resistant Wireless Caregiver Pager Nurse Call System for Restaurant Nursing Home Item Type: Wireless Calling System Material: ABS Watch Receiver Specifications: Working Frequency: 433.92MHz Charging Voltage: DC 5V Battery Type: Lithium Battery Single Watch Receiver Battery Capacity: 300mAh (Included) Working Current: 100±20mA (Vibration and Buzzer Mode) 75±10mA (Vibration Mode) Standby Current: 10±5mA Receiving Sensitivity: -107±2dBm Decoding: Learning Code Water Resistant Level: IPX7 Working Temperature: -20℃ to 60℃ SU U4 Transmitter Specifications: Working Frequency: 433.92MHz Size: Approx. 95x40x15mm/3.74x1.57x0.59in Battery Type: 23A 12V Battery x1 Battery Capacity: 60mAh (Included) Transmitting Current: 10mA±3mA Standby Current: <1uA Open Distance: >1000m Key: 1 Million Times Water Resistant Level: IPX4 Working Temperature: -20℃ to 55℃ Four Key: A, B, C, D