Voice Recorder 4 GB,Memory storage : 4 GB,Recording format : WMA / ACT,Microphone : built-in non-direction microphone,Speaker diameter : 20mm 32Ohm, 0.25watt,LCD screen : 13mm * 36 mm,USB interface : USB 2.0,MP3 data transfer speed : 8Kbps - 320KbpsSNR : 90dB,Sound frequency : 20-20KHz