Amazon.com: RJ45 to RJ11 Cable, 6 Feet Phone Jack to Ethernet Adapter RJ11 6P4C Male to RJ45 8P8C Male Connector Plug Cord for Landline Telephone : Electronics
Amazon.com: Keple 1m RJ11 to RJ45 Cable Phone Telephone Cord RJ11 6P4C to RJ45 8P8C Connector Plug Cable for Landline Telephone (Black) : Electronics
StarTech.com Model RJ25FT 25 ft. RJ11 4 Wire Phone Cable M/M - Walmart.com
RJ11 to BT Landline Telephone Phone Cable Lead Modem FAX Plug BT Socket 2m - 10m | eBay
IDEAL 25-Pack Phone Cable Splice Connector Idc Connector in the Voice & Data Connectors department at Lowes.com