I bought the red version and wore it for 7 months with no problems. Driven 1200 km with it, everything is fine. So when I went to buy a new pair I figured I'd go with the yellow ones. At first I had blisters on my heels when I walked with them and I thought maybe it would go away if I put them on, but now we have a second round of blisters. So I highly recommend the red ones, but the yellow ones, which have a slightly different design, did NOT work for me.