... , factories, nursing homes, clubs, etc. Wireless Calling Service System / Table Calling System / Hotel Service System:Main function:(1) The system is made up of one ... (optional), HJ Multi-function calling transmitter (optional), HB Infrared inductive alarm transmitter (optional), HY Calling transmitter (operated by 1 pc 9V ... , worker, sickbed, or other places you can use this calling system.