The rubber is sturdy and the straps a great quality. The little pouch that comes with it is very well made also, and has a really cool opening and closing mechanism, where you just press the sides together to open and it snaps closed when you let go. My last pair started falling apart after a week (Not this Brand). I wear woman’s US 9 shoe. a lot of the build queues from Chinese manufacturers are very similar and the functionality also doesnt differ. The sound is accompanied by a really warm but deep and heavy bass, so much so I can feel the air around the speaker vibrating. They are narrow. You cant get a spline driver into those screws at the angle of the roof. Dont think these are worth it if you live in a hot place. getting older hasn’t helped so I felt it was time for a proper pair of orthopedic house shoes.