I received online order, discarded the box, and took a 10 minute walk the next day. After 5 minutes, I realized the inside heel felt lower than the forefoot and my lower back began hurting. I called Merrell about return since I no longer had the box. They told me the shoes are not returnable since they were worn outside. Ten minutes - no marks, no dirt. I'm stuck with a pair of shoes I can't wear. User's recommendation: Be very sure to wear inside for at least an hour. They are merciless.