If you have a Telephone Entry Controller installed and you want to electronically allow visitors access into your home, simply connect this Door Strike Relay in-line between the main board a door strike (sold seperately).Once installed, the Doorstrike Relay is easy to use. To close the doorstrike relay while you are already communicating with the door speaker, simply press #7 (or *7). To close the doorstrike relay when you are not communicating with the door speaker, press ## (or **) and then #7 (or *7). For a complete residential telephone access control package, add an intercom unit to your Telephone Entry Controller, which integrates a weather resistant speaker/microphone and a doorbell button. The intercoms are available in several colors to match your home's dcor: oil-rubbed bronze (#50712), brass (#50713), white (#50714) and in satin nickel (50712N).