Then take the other three adapters to other rooms in your property, plug them into wall sockets (not extension leads), and then connect each one to the LAN socket of a device (Smart TV, TV box, laptop, CCTV etc) using the other ethernet cables.
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ZoeRax 2PCS RJ45 Coupler Ethernet Extender 1000Mbps, Cat6A Cat6 Cat5e Ethernet Cable Extender Ethernet Adapter LAN Connector
Aliexpress UK
The TP-LINK TL-PA4010P is a single POWERLINE adapter that functions as an AV600 Passthru Ethernet extender. With a maximum LAN data rate of 600 Mbps, this adapter in white and grey colour provides wired-Ethernet connectivity through its RJ-45 ports. It includes one LAN port for connecting to a network and offers a maximum powerline data rate of 600 Mbps. Ideal for home networking and connectivity, this TP-LINK adapter is a reliable and efficient solution for expanding your network using powerline technology. Tested and working. Single adapter, this will not work on its own.
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Vention Cat7 Ethernet Extension Cable RJ45 Cat7/Cat6 Male to Female Rj45 Ethernet Extender Adapter for PC Laptop Ethernet Cable
Aliexpress UK
2 x BT Mini Connector Passthrough powerline adapters (wired powerline adaptersnot wireless). These Mini Connectors will works with any device which uses an Ethernet cable such as CCTV (with ethernet connection).
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Vention Cat7 Ethernet Extension Cable RJ45 Cat7/Cat6 Male to Female Rj45 Ethernet Extender Adapter for PC Laptop Ethernet Cable
Aliexpress UK
A single preowned Devolo powerline adaptor for your existing dLAN 500 network. Tested & in good working order. The case has gone slightly yellow. It has WiFi and a triple ethernet port (cables NOT included).
eBay
Up Down Left Right Angle Ethernet Adapter 90 Degree and 270 Degree RJ45 8P8C Ethernet Female To 8P8C Male Adapter
Aliexpress UK
They will work with all Internet Providers (BT, TalkTalk, Sky, EE, Virgin etc). 2 x D-Link DHP-300AV Powerline Adapters (wired / ethernet connected adapters. What are Powerline Adapters?. Works with any device which uses an Ethernet cable such as ).
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2500Mbps Ethernet Adapter 2.5G USB 3.0 Type C to RJ45 Network Card Wired Ethernet Gigabit Adapter Lan Card Hub for MacBook iPad
Aliexpress UK
2 x BT Mini Connector v2 (Version 2) Passthrough powerline adapters with DUAL ethernet ports (they are wired powerline adaptersnot wireless). These Version 2 Mini Connectors can be used with any Internet Service Provider - Virgin, Sky, TalkTalk, BT etc.
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M2 RJ45 Network Adapter RTL8125BG Chip M.2 Gigabit Ethernet Network Card 2.5G/1000/100Mbps Ethernet Adapter Mini PCIE
Aliexpress UK
3 x Simpler Networks HP200PT64BT2 Passthrough powerline adapters (wired/ethernet connectednot wireless). As the signal supplied by powerline adapters is usually more stable than Wi-Fi, they are ideal for solving common Wi-Fi problems such as signal drop outs, Wi-Fi dead spots and buffering on devices.
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USB C to 5Gbps Ethernet Adapter RJ45 USB 3.2 Gigabit Network Adapter 5000Mbps Type C Ethernet Card For Windows 10/11 Mac OS 11
Aliexpress UK
5 x BT Mini Connector VERSION 2 Pass-through powerline adapters with DUAL Gig ethernet ports (they are wired/ethernet connected powerline adapters. Each adapter has DUAL ethernet ports (which enables connection via ethernet cables to two internet-enabled devices simultaneously), as well as a passthrough socket so you will not have to sacrifice a wall socket. ).
eBay
2500Mbps 2.5G USB C Ethernet Adapter 2.5 Gigabit Type C to Lan RJ45 Network Card for MacBook iPad Pro USB 3.0 Ethernet Adapter
Aliexpress UK