Product review (5 stars): Genuine Whirlpool product, would give 6 stars.
My belt and pully broke after 11 years on my Whirlpool.  One of them broke, and it took the other with it.  I knew absolutely nothing about dryer internals.  Just search on the web, and you will find plenty of videos.  The hardest part of the install was taking off and putting on those little triangles that hold on the wheels.  Once I gave up on treating them delicately, they went off and on easily.  I think it would be very difficult to break one, so just take charge.  My dryer used to squeak horribly before, but now it is pretty quiet.  I should have changed these parts years ago.  Now I know.

This product is for you if you have a lint screen on top in the back right corner, and if the width of the dryer is 29 inches (not the drum width, the top or front panel width).

PROS: everything
CONS: nothing