The M-SM4 module allows to extend the functionality of the VIDOS DUO video doorphone system. The device allows to connect to the system max 4 internal panels or gate stations in the case when serial connection of devices is not possible.

The device is particularly useful when designing large installations (eg in a block of flats), when there are 3-4 apartments on each floor. In this situation, the optimal solution is to place one M-SM4 module on each floor and from this module distribute the wires to individual internal panels in apartments.

In addition, the product can be used to increase the number of gate stations in the system.