Product review (4 stars): It is keeping my dryer alive!
So this was not too difficult to install.  My Whilrpool dryer is pretty old and either the belt or the tension pulley assembly did not fit correctly- the pulley wheel rubbed against the drive.  Since the belt looked pretty frayed and the tension pulley looked new- I left the old pulley and installed the new belt.

The cause of all of this was one of the bearing wheels was shot and the replacements fit like a glove.  No special tools were needed but please do take the time to understand the configuration of belt and tension system- it will help you as you install the parts and put the dryer back together.