There was a time when we used an alarm clock on our nightstand and set it daily so as not to oversleep. Later, they were replaced by mobile phones that have an alarm integrated, however today we continue to use the alarm throughout the day. Why use? You need not oversleep in the morning before work, or not to forget to do an important thing, there are many cases of using the alarm clock. Today, an alarm on the bedside table not only shows the time, but can even be used as an LED mirror.