RJ12 is backwards compatible with RJ11. Will fit RJ11 ports and also RJ12 ports. BE AWARE OF FAKE 'CAT6'/'CAT6a' CABLES AVAILABLE ELSEWHERE. They're a gimmick. This high-quality cable is designed to connect your devices with RJ11/RJ12 and RJ45 connectors.
eBay
ANENG M469C Multifunction Smart Network Cable Finder RJ45 RJ11 LAN Cable Tester Finder Wire Tracker
Aliexpress UK
The BT VDSL filtered face plate will take the bigger RJ45 plug. Uses a special and expensive extended Shielded RJ11 plug these are much stronger/better crimp so stop any chance of cable pull out due to the cable being strained at angles!
eBay
RJ11 To RJ45 Adapter Data Cable Telephone Male to Male M-M Modular Data Cord Handset Voice Extension
Aliexpress UK
RJ12 is backwards compatible with RJ11. Will fit RJ11 ports and also RJ12 ports. BE AWARE OF FAKE 'CAT6'/'CAT6a' CABLES AVAILABLE ELSEWHERE. They're a gimmick. This high-quality cable is designed to connect your devices with RJ11/RJ12 and RJ45 connectors.
eBay
Noyafa NF-812 Network Cable Tester Rj45 Rj11 Anti-Interference Cable Detector Burn Resistant 100v
Aliexpress UK
Uses a special and expensive extended Shielded RJ12 plug these are much stronger/better crimp so stop any chance of cable pull out due to the cable being strained at angles! Top Quality Cat6a stranded shielded Copper Network Cable made by Excel or Connetix etc (this is more flexible, I doubt I will be making these with solid cable ever, as it will not fit the plugs).
eBay
ANENG M469D Network Cable Tester RJ45 RJ11 Networking Cable Connector Repair Detect Line Finder
Aliexpress UK
Made with Cat6a FFTPtwisted pair cable. Top Quality Cat6a stranded shielded Copper Network Cable made by Excel. I am only making these filtered versions because I get asked for them, personally I would just use any of my cat5e, cat6 or cat6a cables without a filter!
eBay
RJ11 RJ12 6P6C Data Cable, Male to Male Modular Data Cord Straight Wiring Pinout Telephone Handset
Aliexpress UK
7m length RJ12 to RJ12 made with Cat5e Shielded twisted pair cable. Top Quality Cat5e Solid Core Shielded Copper Network Cable. Uses a special and expensive extended Shielded RJ12 plug these are much stronger/better crimp so stop any chance of cable pull out due to the cable being strained at angles!
eBay
3/6/9/12/15/30M RJ11 64C Telephone Extension Cable Hot Selling Telephone Cable Two Core Telephone
Aliexpress UK
The BT VDSL filtered face plate will take the bigger RJ45 plug. Filtered version of our high spec modem cable using a ferrite filter covered with heat shrink tube. Uses a special and expensive extended Shielded RJ12 plug these are much stronger/better crimp so stop any chance of cable pull out due to the cable being strained at angles!
eBay
RJ11 automotive power cord Cable for Escort Passport 8500 X50 9500IX 7500IS Redline 360c MAX
Aliexpress UK
RJ12 plugs are backwards compatible with RJ11. Uses expensive extended Shielded RJ12 plugs these are much stronger so stop any chance of cable pull out due to the cable being strained at angles! Made with Cat6a FFTP twisted pair cable.
eBay
RJ11 6P4C Telephone Cable Cord ADSL Modem 1 Meters
Aliexpress UK