Connect two RJ45 cables together with this inline RJ45 coupler. An RJ45 coupler is useful when you're extending the length of an ethernet cable by combining two rj45 cables together. The ethernet coupler features an 8 conductor 1-1 straight through wiring configuration. Designed to allow you to connect two network cables together. Buy these ethernet couplers today. DS RJ45 Inline 8 Conductor Coupler (IVORY). Ethernet Network RJ45 Inline Cat5 Cat 5e Cat6 Cable Cord Coupler. RJ45 Coupler Female to Female Ethernet F-F by BattleBorn Cable.