One side loosened after a month, but the other side didnt loosen yet, so the bar didnt fall to the floor. I was looking for a slipper that could fit securely, offer traction and had breathable material. Cant complain! These are way better than I expected. The Birkenstock "soft" footbed is anything but. The sound is absolutely terrible. These have a prominent mid hump which gives them a certain solidity and thickness in the mids. There are two annoyances that caused me to remove a star, I recommend these headphones but the annoyances are worth mentioning. clear indication that I received Chinese knockoffs or something smh. Probably the best among Nike mercurial series were victory 6 and Vapor 11!