The Pace Americas DSL Filter for Single Line Phones Model No LFT4-1 is a set of three custom bundle filters with a flat cable design. It features a 6-inch cable length and is compatible with the LFT4-1 model. The filter has a DSL/Phone (RJ-11) female connector B and is designed for use with single line phones. Made in China, this DSL filter is ideal for networking cables and adapters, specifically for computer cables and connectors.This is a bundle set of four single line filters and one double line filter for the input DSL and phone. These were used for two years with no problems.