I've had this for over a month now, I've used it several times. I have a Samsung Galaxy S9 with a case that's pretty thick, and it fits just fine. The material is very forgiving with sizes, it's basically a drink koozie for your phone with a plastic window lol. the arm band material itself is reflective on the outside and on the inside where it's on your arm it's soft foam. the only thing that is a hassle is that it's difficult to use the touchscreen because of my wrap around edge screen, and the light sensor is covered by the foam part of the holder so it looks super dark and I have to manually adjust the brightness. Those are pretty minor issues so I am very happy with it.