You will get more benefit because our excellent quality and reasonable price and there are popular and have a good marketing. 1) Unique design: Wirelessly combines digital music MP3 player and polarized lens 2) Polarized lens: blocks 100% of all UVA, UVB, UVC and harmful blue light 3) Wear glasses with the lenses flipped open when it is dark 4) Supports MP3, WMA and WAV format 5) Memory capacity: 128-1GB 6) USB2. 0, backward compatible with USB1. 1 7) Signal-to-noise ratio: 87. 2dB 8) Playback modes: random play 9) Earphones response bandwidth: 20 - 20, 000Hz 10) Earphone adjustment: can adjust the earphone extenders to fit users' ears, turned up and down-270 degrees rotation 11) Built-in lithium-ion polymer battery: 3. 7V, 150mAh, up to 4. 5 hours continuous 12) Lightweight frame material offers all-day comfort 13) Colors: black, silver 14) Weight: 55g Bluetooth technology (optional): 1) Compatible with different Bluetooth compliant mobile phones 2) Crystal clear sound quality: Range of 10 meters (between hands free and mobile phone) 3) Stylish and lightweight design. Users can talk on the mobile phone hands free 4) Compatible with other Bluetooth devices such as computers, laptops, PDAs and MP3 players mobile phone hands free