This is the first armband I bought to hold my iPhone so I can listen to music while I am running and it works great! I haven't had to worry about it slipping off or anything while running and your iPhone fits securely and safely in its enclosure. You can still easily use the volume buttons on the side and the sleep button even though they are protected from sweat. And the headphone jack is of course, easily accessible. I definitely would recommend anyone in the market for an armband strongly consider this one!
I like that this armband is compact and holds tight to arm. My only dislike is that I need to take my iPhone out of it's everyday case to use it