Features: 1) Uses Sigmatel decode solution 2) Supports MP3 / WMA format 3) Configurable buttons of Prev, Next, Play / Stop, Vol+ and Vol- 4) Power on: system will power on by long pressing (>2 second) play key. Auto repeat all: system will auto repeat all music when power on 5) Reset: if system is down, press Play and Forward key, system will reset, and press Play to power on 6) Built-in Li-battery, cycle charger 7) 5 sorts of EQ 8) Earphone be designed as Siamese, can be tuned by stretch 9) Online firmware update Specifications: 1) Storage capacity: built-in 256M - 512M (optional) 2) Interface: high speed USB 3) Download speed: 500kb/s 4) Battery: build-in 580mA rechargeable lithium battery 5) Charge time: 2 - 3 hours 6) Playing time: 4 - 6 hours 7) Range of output frequency: 20Hz - 20kHz 8) Signal-to-noise radio: 90dB 9) H/N: