Used in pairs (one at each end of the cabling) these economisers allow an additional signal to be transmitted down unused wires in 4 pair cable. The four port version allows four telephones to use a single Cat5e cable. New product: the three port version carries 2 voice + 1 data signal.
![Connection Box Category 5e-F78WhB](https://tuk.co.uk/wp-content/uploads/2021/07/Connection-Box-Category-5e-F78WhB-300x300.jpg)