bt extension cable | Wired-up BT 10m Telephone Extension Cable Suitable for BT and Other Networks
30m Black External 2 Pair Telephone Cable Extension Kit 100% COPPER MORE ON EBAY | eBay
15m (49 ft) BT Extension Kit - BT Telephone Master Socket Box Line Extension Cable Kit 25m 30m 40m Lead | DIY at B&Q
1m RJ11 Cable ADSL Extension Lead Phone Cord Telephone Plug High Speed BT Internet Broadband Male to Male Router and Modem to RJ11 Phone Socket/Microfilter/Landline Wire (Black): Amazon.co.uk: Computers & Accessories
Telephone Extension Kit with BT Plug and Cable Clips – BCE Direct
Telephone Extension Cable Male to Female Lead 1m to 30m Phone Wire Landline | eBay
Telephone extension kit - 3m to 100m lengths – BCE Direct