This armband fits my Samsung J7 Prime perfectly, even with the case on it. It has a very adjustable velcro closure, as well as a similarly adjustable velcro armstrap. The fabric is very soft and stretches just enough. The one thing to note with my phone is that I have to put it in upside downfor the slots to be in place for the headphone jack. Overall I'm super happy and can't wait to go hit the gym!