1) support various audio frequency format Repeat downloading music, support MP3/WMA/WMV and other music format etc. 2) Recording and repeating Repeat recording, including inner or outer recorder and A-B repeat reading function. 3) FM stereo radio Full auto-searching FM radio, the defaulted normal FM band is 87.1~108.0 Mhz. 4) U-disk Portable USB2.0 storage disk: No driver need above WIN98 system. 5) Wireless earphone and monitor function(additional) External emitter, the glasses could be used as a wireless headphone and monitor. 6) Top-class lens Top-class sunglasses lens, Polaroid lens, optical lens for your choosing, resist ultraviolet radiation and plated film. 7) Battery Rechargeable 3.7V polymer battery, play MP3 for 4 hours continually. 8) Power saving Automatic power off when it finish playing MP3 or it is in the stand by for 30 seconds. 9) Led light Indicate different states. Accessories: Users' manual, Charger, USB wire, Car charger(additional), Transmitter(additional) Packing and weight: Model : 0. 046KG/set (N.W.); 1 set/giftbox (8.5cm (L)*8.5cm (W)*17cm (H)/0.226KG); 20sets/small case (36cm (L)*18.8cm (W)*37.5cm (H)/4.52KG); 60sets/small case (60cm(L)*37.5cm (W)*45cm (H)/13.56KG) 15000sets/20" container