PC interface supported:USB
Digital formats supported: MP3/WMA
Signal-to-noise ratio:87.2dB
Playback Modes:Random play
External hard drive function: Yes
Audio Additional features:Auto-power off
Earphones type: Binaural
Mfr estimated battery life :5hours continuous
Charging  Time:3hours continaully
Battery tape/capacity: Built-in Lithium lon Polymenr/3.7v,150mAh
Maximum imput power rating:5VDC,150mA
Voice output power:55mW
Voice output frequency:20Hz-20Khz
earphone impendance:16 Ω*2
Memory Flash:128MB-4GB