Vtin Bluetooth Mini Wireless Headset Compatible for iPhone Smart phone Ergonomic Design: The in-ear part of the earplugs is re-designed to make it fit ear more ergonomically and never fall off, super suitable for hiking, jogging or biking, it makes you feel comfortable, free and relaxing. Sweat-proof design and anti-erosion , worried free about swearting, raining and fog. Binaural 3D surround stereo, greatly enjoy the wonderful music during sports With handsfree function, support answering calls, reject calls, end calls, volume control, forward/backward music control, pausing playing, talking switcher and redialing last number, you won't miss any call during sporting. Build-in rechargeable power, supply 6 hours of music playing time, or 9-day ultra-long standby time.