Product review (1 stars): Cheaply made Junk from China not worth of the Whirlpool/Maytag name.
Cheaply made Junk from China not worth of the Whirlpool/Maytag name.  If it were not a cheap item I would send the second set back.  These are cheesy and cheaply made and are a tight fit for a 4" aluminum flex dryer duct.  I don't know who said they were too big - that would only be the case if you have a 3' duct application, not the standard 4' dryer vent duct.

I wish I had just gone to the big box store and bought the other clamps instead.  If you study the picture you will see that this clamp has to be opened up completely to fit around a 4' duct.  Then the screw does not want to go back in the hole in the other side, as it is a real tight fit.  With some cursing we were able to make these work, but I will not buy them again.