Question: are there different size phone jacks?
Answer: RJ11, RJ12, RJ22 Telephone Modular Plugs (Cable Ends) There are many different types of modular plugs, depending on your application, and the type of cable you are putting these ends on. ... There is RJ11 (6 Position, 4 Conductor), RJ12 (6 Position, 6 Conductor), and RJ22 - Handset Plug (4 Position, 4 Conductor).