the headphone work really well out of the box , with better sound quality than the earbud that come with the iphone . however , I experience malfunction of the volume control after a indoor run on the treadmill -lrb- 10k -rrb- ; perhaps some moisture get into the wiring ? after dry , it again become functional . a rather unexpected problem , since one of the tout quality be water resistance . outdoor running do not seem to cause the same problem . it happen again after a shorter run -lrb- 5k -rrb- , again on the treadmill indoors . I guess the sweat get into the control stick and temporarily render it nonfunctional . overall , I get less than what I expect from a rather pricy headset .