Product review (4 stars): Problem solved.
Based on the symptoms of my dryer (high-pitched squealing noise) the forums suggested I replace the belt, rollers, and idler pulley.  This pack conveniently includes everything, including the triangular plastic clips.  I wish they threw an extra clip or two, as I snapped one during installation (used an old one in its place).  So keep that in mind!  I was also concerned about the new belt because there were clearly rough spots on it.  I used a knife to carefully even it out.  This was for my Maytag Epic Z dryer.