Alarm receivers are small devices with a vibrating motor and a loudspeaker to form a loud signal. A pay is also called one beeper or beeper and is suitable for use in critical situations. A alarm receiver is smaller than a phone or smartphone, more reliable and made specifically for alarm messages. Almost all alarm receivers receive text messages, some alarm receivers can only receive numeric messages.
Alarm receivers have been used to alert large groups of people quickly and reliably since the 70s. Alarm receivers are independent of GSM, power or other networks, which means that the reliability is very high. This technique has proven itself in recent years.