Laser alarm

Robbers and other intruders are becoming smarter every day. Many, like me, do not have an alarm. And if you are not at home, then your values ​​become easy prey for the criminal. You have probably heard of such an invention as lasers. If you touch them, then the siren will conquer. But they are very expensive. Therefore, I offer you this video tutorial, which will show you how to make such a laser at home, spending no more than 1000 rubles.