Top Quality Cat6a stranded shielded Copper Network Cable made by Excel. (this is more flexible, I doubt I will be making these with solid cable ever, it will not fit the plugs). RJ12 plugs fit all RJ11 sockets.
eBay
2/3M Trapezoid Slot Floor Cord Cover Cord Protector Extension Wiring Duct Electric Wire Slot Cable Manage Cable Hider Organizer
Aliexpress UK
BE AWARE OF FAKE 'CAT6'/'CAT6a' CABLES AVAILABLE ELSEWHERE. The cable is shielded with foil and features twisted pairs for maximum signal integrity. Connectors are gold-plated pin connectors that are shielded to reduce CRC.
eBay
Power Cable For Starlink Mini DC To DC Power Cable Power Cable Heavy Duty Waterproof DC Extension Cable
Aliexpress UK
The item must be unused and in its original condition.
eBay
0.6M 2ft 2 Pin Prong Female AC EU Power Supply Cable Cord US Power Extension Cord Lead Wire Power Cord For Desktop Laptop Radio
Aliexpress UK
ADSL 2+ High Speed Modem Cable -. As ADSL speeds increase, your normal phone cable isn t up for the job so to be able to get you a faster Internet connection this High Speed Internet Modem cable will sort you out.
eBay
1m 0.3m USB Extension Cable 3 in 1 USB Charge Fast 3A Charging Date Cable Y Splitter Cable USB Male to USB Female 1 to 3 Cord
Aliexpress UK
🔌RJ11 Plug → RJ11 Plug. Supported Services: ADSL, ADSL2+, VDSL/FTTC Fibre. Type: RJ11 6P4C. 📏 Length options:0.5m / 1m / 2m / 3m / 5m / 10m / 15m / 20m. Lengths Available: 0.5m–20m.
eBay
QOOVI USB3.0 Extension Cable USB 3.0 2.0 Cable Extender For Smart TV PC Xbox One Laptop SSD Data Cord Fast Speed Transfer Cable
Aliexpress UK
Telecoms Extension Cable RJ11 (6P4C) Female - RJ11 (6P4C) Male Flat 5.00 m White This cable is suitable for extending the telephone cable between your telephone unit and the wall box, extending a Modem Router / ADSL connection (From the ADSL Splitter port to the Modem). White 5m.
eBay
DB9 Serial Cable 9 Pin RS232 Serial Cable Male To Female PC Converter Extension Cable 9Pin Adapter Cable 1.5m/3m
Aliexpress UK
BE AWARE OF FAKE 'CAT6'/'CAT6a' CABLES AVAILABLE ELSEWHERE. The cable is shielded with foil and features twisted pairs for maximum signal integrity. Connectors are gold-plated pin connectors that are shielded to reduce CRC.
eBay
USB C to USB C PD 240W Short Cable Fast Charging Type-C Cord 40Gbps Data Transfer 8K Flat Slim USB4.0 Data Cable Extension Cable
Aliexpress UK
Premium-quality Cat5e outdoor-grade shielded cable with durable black insulation and twisted pair construction for enhanced protection against interference. Connectors: RJ45 male to RJ45 male. High-performance Ethernet patch cable with two RJ45 male connectors.
eBay
XH2.54 Y-Splitter Cable Male to 2 Female Connector 26AWG Fan Cable 2Pin 3Pin 4Pin 5Pin 6Pin Power Extension Cord Terminal Cable
Aliexpress UK