Product review (5 stars): Expensive but still worth the money.
Existing bellows somehow developed a hole and began leaking profusely.  This replacement fit like a glove and really wasn't that hard to replace.  The price was about $40 less than I could find it locally in the Portland, OR metro area and it arrived in less than a week.  Replacement cost by a professional exceeded $200.  Just remember to orient the three drain holes at the bottom.  ;-)