Auto Flash - Flasher or other?

[Cthulhu]

As per my signature, I currently have a 2007 1500 and a 2006 3500.  The 07 has a really nice feature for those doing 'lazy lane changes' allowing you to 'tap' the signal arm to have it flash a couple times.  Is that a function of the flasher or something else?  Are their parts interchangeable to add that functionality to the 2006?