RJ11 6P4C 2 Female Socket to Male Plug F/M Telephone Cable Connector Networking Cables - Walmart.com
BT Telephone Line Cable Adapter from RJ11 Socket Female Jack to BS6312 431A Male Plug | British UK Modular Standard Connector to 6P4C for RJ11 universal lead | 4 Wire Converter | White | Keple.com
How to make a Telephone Cable - USOC RJ11 RJ45 - YouTube