Baby monitors are for infants, request assistance with dignity.
Note: Each Transmitter and Receiver are a pair. Under the cover they have a label identifying the channel they are set to. Any dot above the channel number(s) is important. It is possible to assign a second transmitter/receiver pair the same channel as a first transmitter/receiver pair so either transmitter activates both receivers. To do so, using a soldering iron add/remove solder jumpers to the 3x8 pin array so that the solder jumpers match on all the desired transmitters and receivers (or Broadened Horizons can do this for you).