This switch is an inexpensive solution to connect up to 4 audio / video to a TV, projector, or a sound installation.
 
It allows a permanent connection between multiple sources (up to 4) to a single main device.

Once the source selector integrated into a complex audio system, just press the push button switch corresponding to the current source.

In addition to the comfort of being able to change source without affecting connections, this type of device is particularly useful for increasing the life of the mechanical parts of the installation (connectors, plugs, cables), since these will be less prone to frequent handling.