RJ12 to RJ12 Cable 1m 6P6C Flat Extension Lead Phone Cord Telephone Plug Connector Male to Male Router/Modem to Phone Landline Socket Switchboard Lead Data Plug Wire RJ-12 to RJ-12 (White): Amazon.co.uk:
FLAT RJ12 6P6C to RJ12 6P6C Cable Plug to Plug (RJ11 with 6 wire) 5m
RS PRO | RS PRO Male RJ12 to Male RJ12 Telephone Extension Cable, Grey Sheath, 3m | 446-664 | RS Components