Cable Length: ~13.2cm. Casing of this RJ11 to BT Converter is made of durable plastic material. Dimension: ~5.1(L) x 2.1(W) x 2.2(H)cm. Weight: 18g. Use this RJ11 BT Adapter to convert one RJ11 socket to two BT sockets. It allows two telephones or modems with a UK plug to connect to a single RJ11 telephone socket. This RJ11 to BT Adapter is very simple to use. You just plug the adapter into the RJ11 phone socket, and plug your BT cables (not supplied) into the adapter, and that's it—you're done! One end is 6P4C RJ11 plug and the other end is two 6P4C BT sockets. Package Included: 1 x RJ11 Plug to Dual BT Socket Adapter. Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.