Durability aluminum casing with anti-scratch. Stylish design with fluorescent holder to strap onto swimmer goggles. Built in rechargeable battery. International IPx8 waterproof standard. Compliant with high speed USB 2.0 specification. Compliant with Win2000/WinME/WinXP/Vista/Win7, Mac OS 8.6+ and Linux 2.4.0 Use Means: Function 1:When turn on the MP3 Player,it plays the MP3 music. Function 2:FM Radio. 1.Turn MP3 Player on,it plays the MP3 music first. 2.Press the pause then. 3.Press the volume(+) or (-) 3 seconds,you will see the display red light is flashing,it means searching for FM signals. 4.You can press volume(+) or (-) change FM Frequency. 5.Escape:Press the pause key. Memory:4GB Music Format: MP3, WMA Bit rate: 32-320Kbps Temperature Rating: 0 - 50 ¡æ Signal to noise ratio: >85dB Output of earphones: 2 x 4mW Button Controls: Forward, Back, Play/Pause Color:Rose Red Note:Because the pressure of water,the earphone doesn"t have heavy bass effect,it is only for listening the MP3 under water. Not suitable for using it in daily life. Thank you! Package included: 1 x Matek ® Trademark Silicone Wrist Band 1¡Á Underwater Sport Diving Swimming IPx8 Waterproof 4GB MP3 Music Player & FM Radio 1¡Á Free Earphone 1¡Á Free Sleeve & Armband 1¡Á User manuel