The other reviewer has it right - the back zipper rubs horribly and there is just no way to make these work.  When I first tried them on the zipper was instantly uncomfortable, but I figured if I broke the boots in a little it would get better.  Well, I broke them in by watching TV on the couch for an hour and even though I was immobile, I still ended up with red marks on my Achilles tendon area.  I don't even want to think about how much pain I would have been in if I had been walking around.  I took the boots off my feet, zipped them up and stuck my hand inside to feel the zipper area. Sure enough, the zipper bulges way inwards at the ankle area even when there's no foot in them.  It's the design of the boot, and the effect of the big metal zipper teeth rubbing on your skin can be likened to a cheese grater.  The color and style were perfect, but I have to return these.  My boot search continues...