The Aiphone GT-1A is a simple audio intercom that is usually installed at the entrance of a house or building to communicate with people who come to the door. This intercom is suitable for use in residential areas, apartments, and offices. The GT-1A features audio only, making it more suitable for areas that do not have the need for video features or more complex intercom functions. However, the GT-1A is easy to use and quite reliable as it comes with a call button and speaker. It can also be installed in garden or patio areas that are already monitored by cameras. Be sure to follow the installation instructions and technical specifications for optimal intercom functionality.