Product review (3 stars): HMP-12P do not equal EMP-15P pads
EMP-15P pads are 2-1/2" HMP-12P are just shy of 3-1/4"

I didn't see sizes in any of the descriptions of these mineral pads and there was a reference for the EMP-15P pads that seemed to indicate an equivalence to the HMP-12P pads. They aren't the same size.

There you have it, my sacrifice (cause it's not worth shipping them back) is our gain in knowledge!

I imagine they can be cut down.