BT Telephone Line Cable Adapter from RJ11 Socket Female Jack to BS6312 431A Male Plug
BT Telephone Extension Cable 20 Meters Lead Full 6 Wire Male Plug to Female Socket for Office & Home Broadband Cord Compatible with Telephone / Fax / Modem (White) | Keple.com
RJ11 to BT Landline Telephone Phone Cable Lead Modem FAX Plug BT Socket 2m - 10m | eBay
RJ11 4 Wire to UK BT Telephone Socket US Plug Adapter 6P4C 10cm Modem
British telephone socket - Wikipedia
BT Plug 431A 4 Wires Flat Cable R/H Latch White (Unbranded) - Comtec Direct
UK BT Telephone Plug to RJ45 Socket Adapter | Connectec.uk
HSEAMALL One BT Plug to Two UK BT Telephone Socket Adapter Splitter Doubler Splitter: Amazon.co.uk: Electronics & Photo
RJ11 Plug to BT Socket with Tail - rhinocables.co.uk
White RJ11 to BT Plug (BT431A) Crossover Telephone Cable - 3m - Pro Signal | CPC