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
RJ45 vs RJ11: What is the difference between RJ45 and RJ11?
What are RJ11 connectors? Everything you need to know