I can see why these are sold half-price, having now worn them a few times, as the unlined polymer insole is awful. I have never had blisters like it, or not on walks of 4 or 5 miles. I don't like wearing socks with sandals (looks ridiculous), but with these I now have no choice, given that it is difficult to anything to a surface like this. Sole is too flexible too, just as with my other newer Teva, sharp stones hurt through them. My 12 year old one's were much much better. Lasted for years of hard use. The newer one's don't. I won't be buying Teva again.