Product review (1 stars): Be careful.
Don't buy these!  Everything related to the negative comments is true.  I went through two of these and they leaked.  I put the old one on, an Aqua Fresh and no leak.  Also, a very serious addition:  when removing the Tier 1 when it is rotated to remove the water pressure literally blows the filter down on the glass shelf with considerable force with a loud "pop" and giving one a nice facial shower.  Be careful.  These are dangerous!