This Telephone Extension Cable is a high-quality Dencon product that is compatible with various brands. It is a 2m long white cable with a 1:1 connexion split/duplication and RJ11 connectors on both ends. The cable is designed for use with home phones and modems, and it comes with a DSL/Phone (RJ-11) female connector on one end and a DSL/Phone (RJ-11) male connector on the other.
eBay