Product review (4 stars): Don't take your top off
Ordered online and delivery OK.  Instructions leave a lot to be desired.  They talk about removing a part on top if you have a certain unit.  I have that unit and after attempting to remove the top I took out the used filter.  There is no top to be removed.  Item screws right in.  Thankfully I did not apply excessive force to remove the top section.  Otherwise, great product.