DSL Phone Line Noise Filter Adapter for DSL Modem Router Fax ADSL VDSL Router | eBay
Amazon.com: Advantage ADSL Filter, No DSL Output : Electronics
Phone Line Dsl Filter, One Device, Male to Female, 1 Line Noise Filter, for Answering Machines, Telephones or Fax Machine, White, 76246 VoIP - Newegg.com
DSL filter - Wikipedia
80-200 Indoor DSL Filter With Data Port | Tii Technologies