RJ11 Cable Line ADSL Fax Modem Phone Network Jack Micro Filter SplitterAdaptH-wq
This filter/splitter has three RJ11 jacks to do just that. Connect the 'line' jack to your wall outlet cable, and connect the 'phone' and 'modem' jacks to your phone or fax line, and to the modem. Each jack is conveniently labeled.