I'm on my 3rd pair in 2 weeks...most definitely not sweat proof.I bought these specifically to wear while bicycling on my roller-trainer. The first pair was defective out of the box...a lot of crackle from the left speaker. The second pair lasted for 8 days of bicycling before suffering from the "controls won't work" problem a lot of other people are complaining about.Quite simply...if you have no itention of getting sweaty with these on, the audio quality is great, the functions intuitive but depending on your ear shape the headset may or may not feel comfortable. If you are hoping to work out while wearing these, you really should keep looking. Well, either that or Frankenstein some kind of anti moisture solution that Motorola shoulda done in the first place....I'm gonna try silicone sealing my 3rd set.