Purchased this same faucet in 2012, but never registered it.  Had a couple issues with the last one(lime clogging the aerator and not being able to remove the aerator to clean; and the handle became very loose, and could not tighten).  Learned a few things installing it this time, and those problems should not reoccur.  Very easy to install, and looks great and works great this time.  Just make sure you go over the installation instructions several times.  This model did not require an aerator key, so don't look for it.  You can take it off and put it back on by hand.