I use this Kopfphörer (Sennheiser PX 100-II) for a year for sports (jogging, etc) in combination with Samsung Galaxy SII and am very satisfied. On my (big) head of stuck, slips and not suppressed. More comfort and better sound than all In-ear earphones which I had tried (especially any cable noises in the ear and no balance problems!). No sweat, because the ear pads are breathable. I also own Sennheiser HD 598 (open) and Audio Technica ATH M50 (closed). For my taste PX 100-II provides better sound than Koss Porta Pro. I also like his rich bass. Strong buy recommendation!