This is a RJ45 cable 1-to-2 female to female splitter coupler is used for joining the LAN cables or adding the branch cable. This coupler allows two computers to share high speed DSL cable modem and Ethernet ports. This coupler also can be used to combine the two short network cables together to be a long one. - Connects two computers via one RJ45 lines (but only one computer's connection can be used at a time) - Requires two couplers to work together one on each end of the cable. . Illustration: . === router/switch ===>--- (one ethernet cable) ----- 2x PC ==== . where "=" means two ethernet cables ">" and "