3-Station door answering intercom provides second inside speaker. Combine two inside speakers with one door speaker to expand your convenience. Indoor speakers allow you to answer the door from two locations plus talk privately between the two speakers. The two-note electronic chime sounds at both inside speakers when a caller presses pushbutton at door. Respond to callers by pushing 'Door Talk' button on either inside speaker. Door speaker operates hands free. The 'Inside Talk' button lets you speak to someone at other indoor station without the door speaker transmitting for greater privacy. Includes 16V transformer.