Knock at a door, steps and a question «who there?» Set through a small crack, and even simply loud voice … Earlier it was so, but now to shout through a door, and even to risk, slightly opening it, it is not necessary, as there were intercoms. Come will press near an input the button and at you the call will be distributed. You can talk to the visitor and solve, let in to you it or not. Some on-door speakerphones are equipped with chambers that will allow you not only to talk, but also to see the visitor.
Intercoms in private houses are especially necessary and in the big territories surrounded with a fencing is will relieve of necessity each time when someone will come, to run on street, to find out, who stands up for collars.
At us in wide assortment qualitative and reliable intercoms of various types are presented. Address, we will necessarily pick up the device approaching for your purposes.