High-performance in-line DSL filter for phones or telephone equipment sharing a single phone jack. Isolates DSL and home phone line networking signals from voice signal for peak data performance and voice quality. Effectively filters one or more phone devices (standard or cordless phone, answering machine, dial-up modem, fax machine, etc.). Easy to install without tools – just plug the filter cord into any standard phone jack, and plug the phone cord into the filter. Provides a filtered jack for any single-line phone device plus a second unfiltered jack for DSL connection.