This adapter allows adding two devices into an existing phone jack sharing the same line. Perfect solution how to add a fax machine, answering machine, speaker phone, modem, call blocker, etc. to your phone line.
1. Plug the Duplex Jack into any wall jack. Or into a telephone extension cord that ends with a female jack.
2. Plug any two telecom devices into the jack.
Note: most homes are wired for 1 or 2 line service (6P4C). For 3 lines, the home or office must be wired with 6 conductors (6P6C).