Wow, that's a real ferrule. You'll put the lock ring on the tube first, then put the ferrule on the tube, then insert the tube in your fitting and screw it down. Look up how to do compression fittings for household plumbing - Rvenger is correct, these are the same thing.
I am using these in a current build, posted in the sticky. These are really easy to use and I highly recommend them....but...they are sensitive to the tube being very precisely cut. Use a saw or hard tube cutter not the cheap cutters that come in some kits.