It really works and helps me have a very deep sleep. 5 y me llegaron en 5 (pero son 8. A bit uncomfortable at first because the gray area has a ridge where it meets the pink. To begin with I bought 6 of these. kind of. The only thing stopping me from going barefoot was the dirty streets of Bangkok that I was walking on. Used with various headphone amplifiers. A great balance of comfortably and sex appeal. but the flips have been a ?miss? for the last couple years. I got a few pairs of shoes that were really expensive and also these.