The allen key head screws are a great way to torque them nice and tight without fear of stripping the head, although somewhat slow and cumbersome, so be prepared to take your time. I strongly recommend it These seem ok. En efecto, son ajustados por su diseño tipo calcetín, sin embargo, con un calzador entran rápida y fácilmente; incluso, sin desatar los cordones. Birkenstock always produce good quality products, I usually find the slip on sandals too big but these are a lot narrower and therefore perfect for me! Perhaps the 6. They were a little big. The controls. I really regret losing my original pair of these same headphones - which were flawless. I found windscreens that fit my BlueParrot headsets.