High Quality NEW!!! Material: Silicone Coated Dimensions: 12.5 x 12 x 3 cm Weight: 32 g Power: Built in 3.7V Li-Polymer Rechargeable Battery Playback Time: Up to 10hrs Charging: 5V 1A Charge Time: 1.5 - 2hrs Internal Memory: 8GB (up to 2,000 songs!) Operating Temperature Range: 0 - 80°C Storage Temperature Range: 0 - 80°C USB Interface: USB 2.0 System OS: Windows ME/2000/XP/Vista, Windows 7, Mac OS 9.X or higher Supported Formats: MP3 (8-320Kbps), WMA, DRM WMA, OGG, WAV, AAC-LC Comes with 3 pairs of earbuds; Small, Medium & Large Easy to use Adjustable - Its frame is made from PP material which is strong & flexible, can bend it to fit your head's size. Light & Portable Good heat resistance Humanized Design Earplug Bluetooth 4.2 - Clearer sound quality! FM Radio Running Timer - Calculate your exercise steps & consumed calories IPX8 WATERPROOF - Waterproof to a depth of up to 3m! Equipped with a special earplug for swimming, doesn't fall down when worn solidly. Perfect for E-BOOK & playing pre loaded music in any conditions. You can switch order playing or shuffle playing.