Amazon.com: 2× RJ45 Coupler with Extra Shielding– Network Cable Connector & Ethernet Cable Extender (Two RJ45 Jacks, Easy Way to Connect/Extend Ethernet Cables, CAT 6A for up to 10Gbit/s, Black) – by
Amazon.com: RJ45 Coupler, PLUSPOE 2 Pack Ethernet Cable Extender Inline LAN Connector Plugs for Cat5 Cat5e Cat6e Cat7 Cable, Female to Female (Black) : Electronics
50PCS Cat5e RJ45 Network Ethernet Head Lan Cable Joiner Coupler Cable Connector | eBay