RJ11 Dual-Line Splitter (1 Plug, Sockets)
This adapter splits a 2-line setup (i.e. a wall jack where a single outlet has 2 lines) into two separate outlets (L1, L2) as well as maintaining a third outlet in the original configuration (L1+L2).
Some 2-line phones have two separate sockets, one for each line. This adapter will take care of that, simply run one cord from L1 to your phone, and another from L2.
Alternatively, if you want to connect a device (Fax or Modem) to line 2, you may have noticed that a traditional splitter will not provide access to line 2 on the jack. This adapter will take care of that, simply plug your fax or modem into L2 and it will use the 2nd line.
For additional specifications, please review the item specifics.