Natcomm have been manufacturing Fax Switches of the highest quality for over 26 Years. They have proven to be exceptionally reliable and are offered with a Two Year Warranty. Two models are
Amazon.com: GLE2016 In-line DSL Splitter Adapter with Noise Filter for Telephone Phone Fax Accessory (Pack of 2) : Electronics
DSL Filter Adapter for PC Computer Phone Fax Modem Line | eBay