The clock is a receiver (message receiver) that informs about a call. It can be used in cafes to inform the service staff about the order made, customers who want to pay, in nursing or medical institutions and similar situations. Operating distance up to 150m in an open place. Indoors, depending on obstacles (walls), the distance may be smaller. Operating principle: pressing the pager button triggers the bell, vibration or screen indication, which informs the service staff.