So first, yes, I was scared the first time I dipped my smartphone underwater and NO, it is not dead =) I tested the tightness overnight with the paper as shown in the little documentation and then with two XXL smartphones (Samsung Galaxy Note 2 and 3) and they still work today. Terms: in a chlorinated pool, water slides in (in front camera rear + mode is better than GoPro !!) and to the beach, on the sand and in the sea water. The quality of photos and videos is not (or very little) affected by the cover. Very very good value for money!