RJ12 plugs fit RJ11 sockets they are backwards compatible. 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
diymore RJ11 RJ45 Mini Computer LAN Network Cable Professional Tester Network LAN Cable Wire
Aliexpress UK
RJ12 plugs fit all RJ11 sockets. Uses a special and expensive extended Shielded RJ12 plugs these are much stronger/better crimp so stop any chance of cable pull out due to the cable being strained at angles!
eBay
COMNEN RJ11 To RJ45 Adapter Data Cable Telephone Male to Male Modular Data Cord Handset Voice
Aliexpress UK
5m 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
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
HQ 1.5-2m KRONE voice module test cord 110 to RJ11 test head telephone dedicated P-wire test cable
Aliexpress UK
The BT VDSL filtered face plate will take the bigger RJ45 plug. 50 cm length RJ45 to RJ11 made with Cat6a twisted pair cable. Top Quality Cat6a stranded shielded Copper Network Cable made by Excel. 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
USB Serial Cable for APC PDU 940-0144A ,RJ11 RJ12 6P6C RS232 Cable for APC Rack PDU
Aliexpress UK
2m length RJ12 to RJ12 made with Cat5e Shielded twisted pair 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
RJ11 6P4C Telephone Cable Cord ADSL Modem 10 Meters
Aliexpress UK
RJ12 plugs Fit RJ11 sockets. Top Quality Cat6a stranded shielded Copper Network Cable made by Excel. Filtered Version. You cannot call any 'Copper clad aluminium' cable a Category cable or patch lead, as this is an industry technical reference that belongs to the USA TIA and the ISO International Standards Committees.
eBay
TEUCER PCI-E 4.0 X16 Riser Cable Video Card Extension Shielded Flexible 90° Mounting GPU Extension
Aliexpress UK
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, as it will not fit the plugs). 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
Bochara Braided 3.5mm TRS to Dual XLR Female OFC Audio Cable Foil+Braided Shielded For Speakers
Aliexpress UK