FREEFLEX TECHNOLOGY™ - Adapts to any ear size without the need for complicated parts or ear hooks which hurt over time. EXTREME COMFORT - Designed to be comfortable to wear for hours in or outside the gym. WATER & SWEAT RESISTANT - Keeps playing when working up a sweat. MIC + MUSIC & SIRI CONTROL - Activate Siri, control volume, pause/resume/skip music and answer/hang-up phone calls with one button. QUICK CHARGE - Delivers up to 8 hours of playtime for a week of workouts, or a full day of listening. With quick charge technology - recharge on the way to the gym for 10 minutes and get an hour of playtime.